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This work is protected by copyright and other intellectual property rights and duplication or sale of all or part is not permitted, except that material may be duplicated by you for research, private study, criticism/review or educational
purposes. Electronic or print copies are for your own personal, non-commercial use and shall not be passed to any other individual. No quotation may be published without proper acknowledgement. For any other use, or to
quote extensively from the work, permission must be obtained from the copyright holder/s.
Volu M £. T w o
PROBLEM-SOLVING IN THE CONTEXT OF THE GENERAL CERTIFICATE OF EDUCATION ORDINARY LEVEL CHEMISTRY EXAMINATION
APPENDICES
Instruments and Data
Appendix to Ph.D. thesis University of Keele, 1984
Dav id SI imra ing British Council
Introduction and instructions
1. This study Is a preliminary part of a research project concerned with the way in which chemistry students tackle O-level chemistry examination questions. Our interest is not just in your answers but more particularly in how you obtained them; in other words in the thinking process which led to your answer.
2. You are therefore asked, while you try to answer the questions, to THINK ALOUD, and a tape recording will be made of what you say. You should also write any workings you want to use on the question paper and write out your answers in full just as you would in an examination.
3. We often like to fool ourselves that our thinking is more logical and well organised than it really is! For this study it is just as important to know about the ideas which do not work-out or which perhaps seem to be unimportant, as to know about the more successful efforts.So please record the bad or irrelevant ideas and not just the brilliant ones!
4. It will be much the best if you can try to explain everything that is going through your head while you are still working on the answer. This is usually much more helpful than going back afterwards and trying to remember what you were thinking. Occasionally, however, speaking may distract you too much and if this happens it may be best to carry on silently for a few seconds - but be sure to remember and record everything you were thinking.
5. Each session will be conducted by an interviewer and will start with a brief discussion to make sure the instructions are clear. You can have a short "dummy run” if you wish, to get used to the procedure. We will then work for about one hour.
THANK YOU VERY MUCH FOR YOUR HELP WITH THIS PROJECT
(ii)
UNIVERSITY OF KEELE DEPARTMENT OF EDUCATION
PROBLEM-SOLVING IN THE CONTEXT OF O-LEVEL CHEMISTRY EXAMINATIONS
Record of Protocol Collection
Date School Test Ref No
Pupil's first name Sex Ref No
Preliminary Interview data:
1. Interest in chemistry/science
2. Perceived difficulty in chemistry/science
3. A-level plans
4. Career plans
5. Interests/hobbies
General remarks:
Normdat: Mock AH40
Test score:
UNIVERSITY OF KEELE DEPARTMENT OF EDUCATION
PROBLEM-SOLVING IN THE CONTEXT OF O-LEVEL CHEMISTRY: TEST DS/PA/03(PS)
Standard Examination Instructions:
1. No mathematical tables, slide rules or calculators are needed for this test.
2. A few questions may relate to topics or substances with which you are not expected to be familiar. In such questions the necessary data have been provided and you are being asked to think clearly in a new situation.
(iv)
1. When dilute sulphuric acid is electrolysed using platinum electrodes, two gases are evolved.
(a) (i) State the name of the gas formed at the anode ...........
(ii) State the name of the gas formed at the cathode ........
(b) Although the volumes of the gases given off are expected to be in a 1:2 ratio, the volume of one gas actually collected during the early part of the electrolysis is always slightly less than half that of the other.
( i) Why is a 1:2 ratio expected ?
(ii) Suggest a reason why it is not obtained in practice
(c) If the current is kept constant what would be the effect of
(i) increasing the concentration of the sulphuric acid? ....
(ii) increasing the temperature of the sulphuric acid?
(d) Explain how the method of conduction of electricity through dilute sulphuric acid differs from that through a copper wire.
Give the formula for ammonium carbonate..........................
(b) Under suitable conditions water and urea (formula (NH^^CO) can be obtained from ammonium carbonate.
(i) How would you prove that the colourless liquid obtained was really water?
(ii) Urea is a covalent compound. Try to draw its full structural formula.
( v )
3. Give the names of the gases evolved in the following reactions and briefly describe a chemical test for each gas.
(a) Manganese(IV) oxide reacts with concentrated hydrochloric acid:
(i) Name of gas (ii) Chemical test
(b) Iron(II) sulphide reacts with dilute hydrochloric acid:
(i) Name of gas (ii) Chemical test
(c) Ammonium chloride is heated with calcium hydroxide:
(i) Name of gas (ii) Chemical test
(d) Which of these gases normally reacts as an oxidising agent?
4. An experiment was carrieed out to find the approximate heat of neutralisation of3certain acids with certain alkalis. In the first experiment 100 cm of 1M hydrochloric acid was poured into a plastic beaker, and arrangements were made to find the rise in temperature when an equal volume of 1M sodium hydroxide was added.
(a) What is meant by "heat of neutralisation"? ................
(b) Why was a container chosen which was made of plastic?
3(c) In a second experiment 100 cm of 1M nitric acid and an equal volume of 1M potassium hydroxide were used. The rise in temperature was exactly the same as in the first experiment. Explain why this is so.
(d) What would happen to the measured rise in_temperature if the first experiment was repeated with the 100 cm of hydrochloric acid replaced by an equal volume of
(i) 1M sulphuric acid? ......................................
(ii) 1M ethanoic (acetic) acid, CHjCOOH? ....................
F - • \
(Vi)5. The table below gives the number of electrons and the mass numbers of seven different neutral atoms.
E G J L M Q X
Number of electrons 6 9 14 16 18 18 19
Mass number 12 19 28 32 36 40 40
Use the letter at the top of a column to represent the element, or one atom of the element.
(a) Which atoms are isotopes of the same element? ...............
(b) Which two elements are in the same Group of the periodic table?
(c) Which element is a halogen? .................................
(d) Derive a formula for the compound formed when X reacts with L.
6. Crystals of iron(II) sulphate, FeSO^. TI^O, were prepared asfollows. An excess of iron filings was added, a little at a time with stirring, to a solution of copper(II) sulphate in water. A reddish- brown precipitate was formed and the mixture was filtered. The filtrate was evaporated (taking all necessary precautions) until a saturated solution was formed. The solution was then cooled and the crystals were filtered off and dried.
(a) Why was an excess of iron filings used? ......................
(b) Give the name of the substance which had to be filtered off before crystallising the solution.
(c) Which of the substances used acted as an oxidising agent?
(d) Because of the nature of iron(II) sulphate a special precaution had to be taken during the evaporation of the filtrate to obtain a reasonably pure product.
(i) What to you think this precaution might be? ..........
(ii) How might this precaution be taken?
(e) Despite every care the mass of crystals obtained was much less than that calculated from the balanced equation for the reaction. Explain why there is a difference between the actual yield and the calculated yield?
(a) Define oxidation in terns of changes at the atomic level.
(b) In each of the following equations underline the substance which is being oxidised.
(i) „ +++ Fe + (H) F e ^ + H+
(ii) Cu + Br2„ ++Cu + 2Br
Name the industrial processes used in the following:
(i) the catalytic oxidation of sulphur(IV) oxide to sulphur(VI) oxide;
(ii) the catalytic reduction of nitrogen to ammonia.
(a) Give the name of a compound present in pure soap.....
(b) Explain why soap will not lather well with hard water.
(c) Describe a chemical test you might use to distinguish between sodium hydrogencarbonate (sodium bicarbonate) and hydrated sodium carbonate.
(a) Name the hydrocarbon series of which propene, C,H,, is a3 6member.
(b) Try to draw a structural formula for propene.
(c) (i) Give the name of a common commercial product made frompro pene.
(ii) What name is given to the type of reaction used to obtain this product from propene?
(d) ( i) What is a hydrocarbon?
(ii) Is the product you named in (c)(i) a hydrocarbon?
Table Al Students' test scores and other data
School Pupil Sex Test % "Mark" % 0-level AH 4 (Pt 1)
AH4 (Pt 2)
AH4
C 008 F 78 80 A 49 60T— —
109009 M 35 48 A 53 62 115010 F 36 58 B 49 55 104011 M 51 64 B + + +012 F 67 74 A 42 52 94013 M 38 58 B 44 59 103
D 014 M 35 55 B 45 58 103015 M + (53)* -
_ + + +016 M 39 39 B + + +017 M 46 45 B 40 35 75018 M 41 52 B 46 51 97
E 019 M 80 85 A 49 63 112020 F 74 90 A 41 41 82021 M 87 92 A 47 60 107022 M 57 76 B 48 63 111023 F 43 60 B 47 60 107
F 024 M 58 76 A 31 46 77025 M 64 70 A 35 55 90026 M 74 79 A 40 60 10002 7 M 72 79 A 48 52 100028 M 72 81 A 35 60 95
* Data not Included In calculations + Data not available
Form for recording strategies and errors
Principalstrategies
Studen
t
Score
Abor
tive
attempt
Corr
ect/
sound
Correc
t/unso
und
Not
corr
ect
Checking strategies
A!B C D 0 G No te s
Table I tem
(x)
Summary of conventions employed in the transcripts
Ex : examiner/author
008 etc : student's reference number
underlining
: pause (up to about 10 seconds)
: irrelevant passage omitted
: verbal emphasis? : questioning tone
(?); ( ?) : previous word or words uncertain
? [unclear] : one word unintelligible
?? [unclear] : more than one word unintelligible
t ] : author's observation or comment
[Reads aloud] : the protocol was not transcribed whenstudent merely read an item without obvious inflection or comment
PUPIL 008 - TRANSCRIBED PROTOCOL (TEST 03)
1(a) 008 [Reads to herself] - um - oxygen's formed at the anode because
it's in dilute solution - there's hydrogen ions and oxygen ions um
hydroxide ions - and sulphate ions - and hydroxide ions are discharged
as opposed to sulphate ions -
Ex Right now - you gave me the answer straight away..... are you
sure you got it through applying the logical processes? - you didn't
sort of imagine the experiment - Hoffmann voltameter or something
like that?
°°8 No - 'cause we never did that..... hydrogen at the cathode -
because its sulphuric acid and hydrogen ions are the only positive
ion there - [writes].
1(b) 008 [Reads to herself] - er - panic -
Ex [Discusses procedure re reading/writing - encourages to think
aloud].
^ 8 Well I know that more hydrogen is evolved as opposed to more
oxygen - I'm try - I'm guessing that it's probably the solubility
of oxygen - is less than that of water [?] -
..... you said you know there's more hydrogen than oxygen — why
do you think that?
008 - the electrolysis is that - is like that of water - [writes] -
I'm putting it's like the electrolysis of water - so that's the rat
- that's why the ratio is 2:1 - like that of water - two hydrogens
to one oxygen - and why is not obtained in practise - probably one
greater solubility than the other - [writes oxygen more soluble].
l(c)(i) 008 [Reads aloud] - if you increase the concentration of the
sulphuric acid — there's more ions present — therefore you'Id get
more gas given off - [writes].
- A1 -
l(c)(ii) 008 [Reads aloud] - don't think it would have any effect [puzzled
expression] -
Ex Why do you think no effect?
008 -
Ex Just that you can't think of any effect that it would have?
008 I can't think - reason - why increasing the temperature should
affect it - possibly the ions move quicker - 'cause if you heat a
substance the particles move more quickly - so could be that the ions
move quicker - so the gas is produced more rapidly [crosses out "no
effect" and substitutes new answer - note how easily deflected from
correct answer].
1(d) 008 [Reads aloud] - copper wire's got electrons in it and the
movement through a metal by electricity is by electrons - current
is carried by electrons -
Ex Do you just remember this?
008 I just remember this - yes 'cause a copper wire - in Physics
actually - we heated a piece of wire at one end and it conducted to
the other end due to the movement of electrons - urn - conduction
through dilute sulphuric acid is due to ions — [writing] — movement
of ions in acid, movement of electrons in wire.
Ex [Discusses procedure and encourages]......could we go back to
(b)(i) - why is a 1:2 ratio expected? - now - the question -
presumably when you read this you say oh well its asking me for an
explanation of something - and your explanation was, I think, that
it's basically electrolysis of water.....
008 Yes.....
Ex and - I presume you were thinking water's 1^0
- A2
008 Yes
Ex two hydrogens one oxygen - but to give a full explanation you
might need to give a little more information [goes on to suggest that
Avogadro's law has been assumed - 008 appears "au fait" with this
but not with the idea it should be referred to in her answer - she
makes little response].
2(a) 008 [Reads aloud] ammonia - forms compounds of NH^ - there's twice
as mu - it's got a valency of 1 - carbonate's got a valency of 2
therefore you need 2 molecules of ammonia to one molecule of carbonate
[writes correct answer including brackets].
2(b)(i) 008 [Reads aloud] - anhydrous copper(II) sulphate - goes blue if
you add water to it - so it could be tested like that - [writes].
2(b)(ii) 008 [Reads aloud] urn - no idea - it's got carbon in it - er its got
a double bond to the oxygen and it's got two Nl^ group ~ erm - that's
about as full as I can draw it [has drawn as she spoke] -
Ex What should the valency of carbon be?
008 [v softly] four -
Ex What about the valency of nitrogen?
008 - three - there's [counting] one - three - three- I think its
about right - does it mean by "full structural formula" that you have
to draw electrons in? [Note preparedness to re-consider answer
apparently despite some confidence in its correctness - merely because
Ex is asking questions about it] -
Ex It's up to you - no, let’s leave it at that. [Asks 008 to try
to explain what she understands by each question ajs she reads it.]
- A3
3(a) 008 [Reads aloud] Concentrated hydrochloric acid's an oxidising agent
- so it must be chlorine - I'm writing the answer down - chemical
test for chlorine - it bleaches - blue litmus - first pink then white
- that's what we did in class - I'm writing the answer down - must
be moist blue litmus - [writes].
Ex You're remembering that test because you've written it in exams
a lot, or because you've been told it a lot or you remember doing
it or what?
008 We've done it in class a lot.
Ex Actually doing the test?
008 Yes -
3(b) 008 [Reads aloud] - hydrogen sulphide gas - ?? [unclear] by swapping
the radicals over - [writes] - chemical test for hydrogen sulphide
is lead acetate paper - which goes black because I've done it in class
- or lead nitrate paper.
3(c) 008 [Reads aloud] - ammonia - by swapping the radicals over I would
think -
Ex So you worked that one out rather than remembering it?
008 Yes - I don't remember that one - chemical test for ammonia -
bleaches moist red litmus - no - turns red litmus blue because its
an alkaline gas and there's not many alkaline gases - [writes] -
Ex Why do you think you thought it bleached litmus at first? -
008 - getting it muddled up with chlorine - I suppose because they
both smell funny - I'm writing the answer down -
[Ex queries answer to c(i) and points out that swapping radicals
yields ammonium hydroxide and calcium chloride] -
- A4 -
008 - ammonium hydroxide is ammonia solution which is ammonia in
water - and that decomposes easily to form ammonia plus water -
Ex If you could try and tell me.
008 Yes -
Ex I know - it's very difficult because people don't usually think
aloud - carry on -
3(d) 008 [Reads aloud] - panic! - just wondering which of them does -
chlorine, hydrogen sulphide, ammonia - hydrogen sulphide's a reducing
agent - chlorine - comes from an oxidising agent - could be
chlorine -
Ex Now you're pausing quite a bit - what are you trying to think?
You're trying to work something out, I can hear the wheels grinding,
but - what is it you're trying to do - are you thinking about
oxidising agents - making up lists of oxidising agents - or are you
trying to think about each of the gases or what are you doing?
008 Well I know hydrogen sulphide isn't an oxidising agent - that's
a reducing agent from the list -
Ex Right -
008 Chlorine comes from hydrochloric acid which is an oxidising agent
when its concentrated - but I don't know whether that is - ammonia -
doesn't come in the list anywhere — so I think it must be chlorine
[writes].
4(a) 008 [Reads aloud] - can remember this in my exercise book - all
listed down - it's when - one mole of water is produced from one mole
- no it's produced from the reaction - of an acid and an alkali -
writing it down [does so] - seems to be a big space there and I've
only filled two lines of it [has omitted any reference to heat!].
- A5
4(b) 008 [Reads aloud] - maybe 'cause the plastic would get hot -
possibly - then again - if the acids were too concentrated they
might wear away the plastic - I think it's so that the heat could
be determined - I'm writing it down [does so adding "as plastic feels
heat" ].
4(c) 008 [Reads aloud] 'erm - they must produce the same amount of water
- that's the only possible reason - writing it down [does so - note
how obvious this part is given the definition 008 quoted! long pause
as she adds to the answer without comment].
4(d) 008 [Reads aloud] - sulphuric acid - and sodium hydroxide - that
equation you need two - and you get two molecules of water produced
- I can see the balanced equation in my mind - er - the temperature
rise should be twice as much I think - writing it down [does so] -
part (ii) IM ethanoic acid - is used - trying to work out the equation
- ethanoic acid plus sodium hydroxide - sodium ethanoate - ??
[unclear] the acid's monobasic - so I think you'Id still get the same
temperature rise because only one molecule of water would be formed
- writing it down [does so].
Ex Could we go back a couple - first of all you'Id met ethonoic acid
before?
008 Yes.
Ex Strictly it's not in the syllabus.....
008 Yes - ? [unclear] the reactions of alcohol.
Ex Yes..... could you go back and look at what you've written for
(a) - 4(a) - ?
008 Yes -
Ex Check the question again and perhaps read it back - see if you're
satisfied with that answer.....
- A6
^ .,x
008 [Reads answer aloud] - so it's the heat produced - urn - [adds
heat produced when..... ]
Ex I wonder why you missed that out? Have you got any idea?
008 Didn't read the question - probably - [Ex comments and asks 008
to go on to the next question - gives encouragement "you're heading
for about 80% so far"].
5. 008 [Reads aloud first para] - and it gives the table in front of
me - [reads the rest aloud up to and including (a)] - I'm going to
have to work out the electron structure [in fact this is NOT necessary
for part (a)] - I'll write it down underneath each - 2, 6, - no 2,4
Eis 2, 4 G - 2, 7, J is 2, 8, 4, L i s 2, 8, 6, M i s 2, 8, 8,
Q is 2, 8, 8 and X is 2, 8, 8, 1 [all this without significant pause]
- from this I can work out my answers - part (a) [reads aloud] -
isotopes have the same — um — number of protons — and because there's
the same number of protons as there is electrons - then the number
of electrons tells me how many protons there are — and so two with
the same number of protons are isotopes - that is M and Q.
5(b) 008 [Reads aloud] - they have the same number of electrons in the
outer shell - which is - you've got one 2, 4 and 2, 8, 4 which is
E and J -
5(c) 008 [Reads aloud] - halogens are in group VII and therefore they've
got 7 electrons in the outer shell - and therefore that is G - part
(d) -
5(d) 008 [Reads aloud] X is in group I because it's got one electron in
the outer shell — L is in group 6 because its 6 electrons in its outer
shell - therefore X is an alkali metal - L is in the same group as
- A7
\
oxygen and sulphur - which are the only two I know out of that group
- so L's got a valency of two because the valency is either the number
of electrons in the outer shell or eight minus the number of electrons
in the outer shell - therefore X has got a valency of one L has got
a valency of two therefore it would be X2 L -
6(a) 008 [Reads aloud] - this was - iron's above copper in the
electrochemical series and therefore iron will displace copper from
a compound - so it's to make sure all the copper's been displaced
- you got iron(II) sulphate and not any copper(II) sulphate when you
evaporate - I'm going to write the answer down [does so] .
6(b) 008 [Reads aloud] - I don't know - iron was added to copper(II)
sulphate and a reddish-brown precipitate was formed [reading] - the
mixture was filtered — well if it's formed iron(II) sulphate it must
be just copper because that's the only thing left -
6(c) 008 [Reads aloud] - oxidising agents - transfer of oxyen - no it
can't be - transfer of electrons - hydrogen or valency - well valency
hasn't increased and there's no transfer of oxygen - so the copper(II)
sulphate must be the oxidising agent - because the iron is on its
own - there's no oxygen or anything - ? [unclear] - the iron is aO I
molecule, the copper is an ion - copper is an ion so it's Cm - plus
sulphate ion [writing] - and the iron - I'm working out the equation 2+- Fe goes to Fe - it forms an ion - to do that it must gain two
electrons — and therefore it's gaining electrons from the copper —
copper was an ion which lost two electrons — to form a copper atom
therefore it must be the copper(II) sulphate which is an oxidising
agent - [writes this as answer although she has described the electron
tansfer the wrong way around!]
- A8 -
6(d) 008 [Reads aloud] - don't know - iron(II) sulphate - does it oxidise
to iron(III) sulphate? - or does it decompose on heating? - thinking
- what is the special precaution - the question - no idea - iron(II)
sulphate erm - probably oxidises to iron(III) sulphate - so the
precaution must be taken for that reason - but what precaution - [all
this answer punctuated with longish pauses, 5/10 sec] - don't know
- shall I miss it out or shalln't I? - part (ii) I could do - I'm
writing it down - [repeats the words as she writes] - "To stop the
product oxidising to iron(III) sulphate" - why might it be taken -
oh [looks at question again] I've put those in the wrong order - I've
put the answer to question (i) in part (ii) - so [rewrites under (i)
and crosses out under (ii)] - "How might it be taken" - no idea -
can't heat it in a sealed container - or could you - I'll put it down
[does so] -
Ex If you think oxidation's the problem, what would be the oxidising
agent?
008 The oxygen in the atmosphere -
Ex I see.
008 - but then again - I'll leave that and go on to (e) [fails to
consider other ways of excluding air].
6(e) 008 [Reads aloud] - urn - the copper(II) sulphate's in water,
therefore there was water present - out of the water will boil off
- the excess water will boil off - that's what I think the answer
? [unclear] - and some may be lost due to splitting [says and writes
"splitting" instead of "spitting"] - I'm reading the question again
- the filtrate was evaporated taking all necessary precautions - till
a saturated solution was formed - so if we're trying to get it
concentrated - you would take precautions - it might decompose if
it becomes very concentrated - possibly - leave it and go on to the
next one -
- A9 -
Ex OK - you sound as if you're not quite satisfied with your answer
there.
008 No - I'm not -it's just these last two - part (d) and part
(e) .....
7(a) 008 [Reads aloud] - atomic level - due to - must be the electron
structure - because the electron's the only thing in the atom that
takes part in the oxidation - oxidation -
Ex Now how are you getting this? Where's it coming from?
008 urn - well it's at the atomic level so it can't be oxygen that's
involved or hydrogen .....
Ex Sorry - I got that from what you were saying before, but - you're
writing down a definition now in terms of electrons - where are you
getting it from? - it's just memorised or .....
Ex ..... or putting it together from bits and pieces or .....
008 - from my exercise book 1 think - oxidation - now one's the
increase in the number of electrons and one's the decrease - I always
remember it - the oxygen - in oxidation - oxidation is the addition
of oxygen therefore - the valency goes down - not the valency the
electrons - it's a loss of electrons because those two are opposite
- that's how I always remember it - so oxidation [writes] is the loss
of electrons - it seems to be a big space and I've only written a
bit - I'm not sure about that -
7(b) 008 [Reads aloud] - so - iron 3 plus, plus hydrogen goes to iron
2 plus, plus a hydrogen atom - so the valency has gone down which
is the - the valency of the iron has gone down - which is a decrease3+ 2+- no it's gained electrons to go from Fe to Fe - the electron's
»
cancelled out one of the positive charges - and therefore the iron
3 plus must be oxidised by the hydrogen [wrong way round!] - it is
- A10
also the addlton of - It's the addition of hydrogen [surprised tone
- recognising contradition] - oh I'll leave that one! - part (ii)
[reads aloud] - copper and bromine goes to copper ions plus bromine
ions - copper is an atom - bromine is an atom - um and it goes to
copper ion and bromine ion - so - I'm writing the equation - copper| j
goes to copper ions [writes part equation Cu — ^ Cu + 2e] - two
electrons - copper goes to copper ions plus two electrons so it's
got to lose electrons to form a copper ion - loss of electrons is
an oxidation - bromine's a negative ion it's gained electrons -
therefore the copper must be oxidised [underlines Cu].
7(c) 008 [Reads aloud] - sulphur(IV) oxide's sulphur trioxide -
sulphur(VI) oxides's - um - sulphur(IV) oxide's sulphur dioxide and
sulphur(VI) oxides's sulphur trioxide - industrial processes involved
- I wonder what that means - industrial process - that's an oxidation
'cause oxygen is added - but there's no name given to the process
- um - the oxidation of sulphur dioxide to sulphur trioxide - for
sulphuric acid - industrial processes -it only gives a short line
- so it's just the addition of oxygen - industrial processes used -
it's not called a special process - Contact process is preparation
of sulphuric acid - must be oxidation - addition of oxygen
[reluctantly writes this down and reads part (ii) aloud] -
reduction of nitrogen to ammonia - they give a longer line for that
- I'm not sure about that - we've always done the catalytic oxidation
of ammonia to give nitrogen - or an oxide - and water - the opposite
way round to what I'm used to it - the industrial processes used -
I'm not sure what the question actually means - nitrogen to ammonia -
Ex Do you know a process where nitrogen is turned into ammonia? -
and which is an important industrial process? -
008 [Immediately] - the Harber process but - an industrial process
- All
- in that case that should be the Contact process - [muttering] -
that should be, possibly, the Harber process [writes these in]. [In
reply to Ex's question felt she was not put off by unfamiliar
references to catalytic oxidation and reduction - but by the phrase
"processes used in"].
8. 008 [Reads aloud] - pure soap is - soap of stearic, palmitic or oleic
acids - name the compound - soap is C^H^COONa name a compound -
compound present in pure soap [all sotto voce] - know the
formula of soap, know the name of soap — name of compound present in
soap - [eventually writes sodium stearate unhappily].
8(b) 008 [Reads aloud] - um - hard water is calcium hydrogencarbonate -
contains calcium hydrogencarbonate — and the calcium hydrogencarbonate
reacts with the soap to form sodium hydrogencarbonate and calcium
stearate — which is a precipitate of scum — [brief interruption —
008 re-reads] - soap will not lather well with hard water - 'cause
the calcium ions in the water — no — yes — 'cause the calcium ions
in water [writing] - will not let the soap react as it should -
calcium ions react with the soap to form a precipitate of scum. To
form a lather you have to add sufficient soap to remove the calcium
ions. [Ex queries answer to 8(a)] -
008 - I've put - the name of a compound present in soap - I've put
sodium stearate — which is the formula of — the name of soap - or a
soap -
Ex You're a bit worried about the wording again? .... .
008 ..... Yes ......
Ex We'll talk about it at the end when you've finished ......
8(c) 008 [Reads aloud] - sodium hydrogencarbonate - I'm wondering how
- A12
■
you do this - sodium hydrocabonate decomposes to sodium carbonate,
carbon dioxide and water - hydrated sodium carbonate - is washing
soda - er Na2 C03 ’10H20 - erm - add one to hard water I suppose -
which will soften it - hydrated sodium carbonate softens hard water
and sodium hydrogencarbonate doesn't - that could possibly be it -
I'm writing it down - [writes],
9(a) C)08 [Reads aloud] - C-H, - from the formula C H, - one is doubleJ u n Znthe other which is an eth - an alkene - [confirms that she is familiar
with alkenes in reply to Ex's question],
9(b) 008 [Reads aloud] - there's got to be one double bond - alkenes have
one double bond - it's got 3 carbon atoms in a line - it's got 6
hydrogen atoms [drawing 3 C's with single bonds and 2 Hs by each]
urn - one's got to have the double bond somewhere - so that's only
got 3 [counting bonds to each carbon] - that's got 4 - that's only
got 3 - that possible won't work - I'm going to have to rewrite the
hydrogens - if I can find a rubber -
H[x We'll let you cross it out.
008 - I know I've got to have 3 Cs in a row - if I put the double
bond between one of them - then that's got to have two hydrogens -
that's got to have one hydrogen and that's got to have three [drawing
correct structure as she speaks] that works easier - one, two, three,
four - one, two, three, four - one, two, three, four [in reply to
question confirms she is counting bonds to each carbon],
9(c)(i) 008 [Reads aloud] - calor gas - camping gas I think -
Ex Well - it's a bit unfair because propene strictly isn't in your
syllabus - camping gas in fact contains propane - the alkane - urn
as you say it s one of the alkene series and you should have studied ethene .....
- A13
you do this - sodium hydrocabonate decomposes to sodium carbonate,
carbon dioxide and water - hydrated sodium carbonate - is washing
soda - er Na2 C0 ,j. lOI^O - erm - add one to hard water I suppose -
which will soften it - hydrated sodium carbonate softens hard water
and sodium hydrogencarbonate doesn't - that could possibly be it -
I'm writing it down - [writes].
9(a) 008 [Reads aloud] - C.H - from the formula C H. - one is doubleJ u n Znthe other which is an eth - an alkene - [confirms that she is familiar
with alkenes in reply to Ex's question].
9(b) 008 [Reads aloud] - there's got to be one double bond - alkenes have
one double bond - it's got 3 carbon atoms in a line - it's got 6
hydrogen atoms [drawing 3 C's with single bonds and 2 Hs by each]
um one's got to have the double bond somewhere - so that's only
got 3 [counting bonds to each carbon] - that's got 4 - that's only
got 3 - that possible won't work - I'm going to have to rewrite the
hydrogens - if I can find a rubber -
Ex We'll let you cross it out.
008 - I know I've got to have 3 Cs in a row - if I put the double
bond between one of them - then that's got to have two hydrogens -
that's got to have one hydrogen and that's got to have three [drawing
correct structure as she speaks] that works easier - one, two, three,
four - one, two, three, four - one, two, three, four [in reply to
question confirms she is counting bonds to each carbon].
9(c)(i) 008 [Reads aloud] - calor gas - camping gas I think -
Ex Well - it's a bit unfair because propene strictly isn't in your
syllabus - camping gas in fact contains propane - the alkane - um
as you say it s one of the alkene series and you should have studied ethene .....
- A13 -
008 ethene - yes
Ex ethene [008 uses different pronounciation] you call it - yes -
just by companion with ethene - and what that's used for .....
008 [interrupting] ah - polypropene - that's it.
[Reads aloud] - polymerisation [almost contemptuously].
No thinking needed for that?
no [writes answer].
9(d)(i) 008 [Reads aloud] - it's a compound of hydrogen and carbon only -
Ex You remember this defination from your notebook or? .....
008 - um - hydrocarbon - yes -
..... or did you just work it out from the name?
008 ~ Yes - we've burnt hydrocarbons - that was it - from the
experiment - [writes answer].
9(d)(ii) 008 [Reads aloud] - (c)(i) - polypropene - a hydrocarbon - no
[firmly] - prop - no - propene - is carbon and hydrogen - yes it is
[slightly surprised tone] - even if it's a polymer it's - it's still
got just carbon and hydrogen on their own - [goes on to discuss
mistakes with Ex].
[008 was unable to improve her answer to 2b(i) (proving a liquid is
water) even with considerable discussion of why her test for the
presence of water was inadequate.
On returning to item 3 Ex pointed out that cone HC1 was not an
oxidising agent and 008 immediately volunteered that was -
no response to Ex's suggestion that she might have confused cone HC1
with cone H.S0..
9(c)(ii) 008
Ex
008
- A14 -
008 ethene - yes
Ex ethene [008 uses different pronounciation] you call it -
just by companion with ethene - and what that's used for ...
008 [interrupting] ah - polypropene - that's it.
9(c)(ii) 008
Ex
008
[Reads aloud] - polymerisation [almost contemptuously].
No thinking needed for that?
no [writes answer].
9(d)(i) 008 [Reads aloud] - it's a compound of hydrogen and carbon only -
Ex You remember this defination from your notebook or? .... .
008 - um - hydrocarbon - yes -
..... or did you just work it out from the name?
008 ~ yes - we've burnt hydrocarbons - that was it - from the
experiment — [writes answer]•
9(d)(ii) 008 [Reads aloud] - (c)(i) - polypropene - a hydrocarbon - no
[firmly] - prop - no - propene - is carbon and hydrogen - yes it is
[slightly surprised tone] - even if it's a polymer it's - it's still
got just carbon and hydrogen on their own - [goes on to discuss
mistakes with Ex].
[008 was unable to improve her answer to 2b(i) (proving a liquid is
water) even with considerable discussion of why her test for the
presence of water was inadequate.
On returning to item 3 Ex pointed out that cone HC1 was not an
oxidising agent and 008 immediately volunteered that Mn0 2 was -
no response to Ex's suggestion that she might have confused cone HC1
with cone H_SO..
J - A14 -
\
On being advised that she had fallen into a trap on 4(d)(i) 008
suggested that an acid salt might be formed but was unable to take
the argument further. 008 queried (d) and (e) on item 6 but was
unable to contribute to the discussion which had to conclude at this
point] .
TAPE ENDS
- A15
PUPIL 009 - TRANSCRIBED PROTOCOL (TEST 03)
1(a) 009 Well the gas at the anode will be a negative one - probably
hydrogen - shall I put it in?
Ex Yes - write it in just as you would in a test. - How do you know
it will be a negative one?
009 Because the anode's positive - state - state the name of the
gas formed at the cathode - that'll be a positive one probably -
Ex So now I can hear the wheels going round - you're trying to think
of ? -
009 Yes I can't think of a positive gas - maybe this is hydrogen,
'cause hydrogen's H when its in an acid — and the other one could
be oxygen 0
Ex you're obviously thinking something over in your mind now. What
is it?
009 - Yes.
Ex Try and say it aloud if you can -
009 Yes - which gas goes where -
Ex I can see why you hit on hydrogen but why have you hit on oxygen
as -
009 because 0~ - 0H_ - it could be combined at the anode - think
I'll put 0H_ for the first one then H+ for the other - [does so -
note he writes ions although asked to name gases - also that 0
was corrected at last minute to OH without explanation — not all
thinking being verbalised] — do you want me to go on to the next one?
Ex - Yes, just carry on - urn - perhaps you can say "I'm starting
part (b) now."
1(b)(i) 009 Yes - part (b) now - the gas is given off in the 1:2 ratio so
that means oxygen probably is there because it could be water - in
all - that's been electrolysed - and leaving the more concentrated
acid [note confirmation of earlier answer - some doubt appeared to
- A16 -
have been resolved] so above it's probably right. - the ratio 1:2's
expected because oxygen's got a valency of 2 - so when you're
splitting it there'd be two hydrogens to every - oxygen - [writes] -
going on to part (ii) now. [Writes only, "valency of oxygen is two"
with no reference to his knowledge that water is being electrolysed
and that this is "two hydrogens to every oxygen" - let alone to
Avogadro's law.]
l(b)(ii) [Reads] Might not be obtained in practice because it might
recombine - I'm not sure on that one - shall I just leave it?
Ex Well - if you'Id leave it in the actual exam then fine - but.....
009 - I think I'Id leave it to the end - that one - because I might
see something in the questions below to give me an idea to what it is.
1(c) [Reading] "If the current is kept constant what would be the
effect of increasing the concentration of sulphuric acid?" - What
does that mean? - I'm not quite sure?
Ex Well unfortunately I wouldn't be there - so I can't help.....
009 Yes - I'm not sure quite what the meaning of the question is
there -
Ex You're reading it through again are you?
009 - yes - er - less - er gases would be liberated - at the - er
- anode and cathode - because - - - it's being electrolysed and it's
going more concentrated anyway so if you have concentrated there won t
be as much - er - ions to electrolyse -
Ex [Encouraging to continue] I see - yes? So you're writing that
down?
009 - yes [Writes only a reason why he thinks there will be less gas
- forgetting to mention what the effect will be at all although this
- A17
\
is all he is asked for]. [Reads part (ii)] increasing the temperature
of the sulphuric acid - I don't suppose that would do anything -
doesn't actually change it unless the water in it is evaporated, then
it would completely stop near enough that would - 'cause the water
would be going - so I think we'll put that down - increasing the
temperature would be releasing the water so there'Id be nothing to
electrolyse [writes] -
1(d) 009 [Reads] "Explain how the method of conduction of electricity
through dilute sulphuric acid differs from that through a copper
wire." - well in copper there's free ions so it travels by that -
and in sulphuric acid it — er — it would - well its free ions through
a copper wire that cause it so I'm writing that down -
Ex Yes - and you're still thinking about the sulphuric acid? -
009 Yes -
Ex When you get back to it try to do the thinking aloud - if you
can - I know it's not easy 'cause we don't usually think aloud
but.....
009 - well I don't think it's conducted through the sulphuric acid
as such but its conducted through the ions that are liberated — they
have something to do with the conduction — because when it gets more
concentrated it slows down [note reference to his own earlier — and
wrong — answer] - so it must have something to do with them — [writes]
- I've put free ions in copper wire but the ions are in solution in
the sulphuric acid — 'cause I don't think X shall think of anything
more for that [but again fails to write out fully] - so I might as
well put it down - 'cause you'll probably get some marks for it!
Ex Well that sounds very sensible! - OK - before we move on to
2 let's just check back - you're doing fine — and — er - when you say
in b(i) - you've got a 1:2 ratio because there's twice as much
- A18 -
hydrogen as oxygen - that's fine as an explanation and it's correct
but do you think it's an adequate explanation? - do you think that
goes as far as they want you to? - Is it enough to say there's twice
as much hydrogen as oxygen? -
009 Yes - well I did mention that it had a valency of 2.
Ex Yes, you did [in fact later inspection showed that this
was all 009 had written though he did refer to 2H's to each 0 on the
tape].
009 - yes - I don't suppose there's much else you could put really.
Ex Well - if there's twice as many atoms of hydrogen as there are
atoms of oxygen, why should there be twice the volume?
009 - Because all gases are at a constant volume at er - the same
volume at - one temperature - 20°C -
Ex You were assuming that?
009 Yeh — because all gases occupy the same volume at - a certain
temperature..... [discussion terminated and 009 asked to
continue].
2. 009 [Reads] "Give the formula of ammonium carbonate". - Well ammonium
is NH^+ - so I'll write that down - and carbonate is CO^ - it must
be a minus sign - yes, that's right - that's the formula for it [has
written NH,+C0_ ].4 3
2(b) Ex Are you reading part(b) now?
009 Yes - reading part (b) -
Ex It often helps if you try to say what you're thinking while
you're reading it - you know - how do you see the question - what
does it seem to be about? - you know -
009 It seems to be about how you could make liquids from this -
er compound that we've already been given - er [reads] "how would
- A19 -
mm
you prove that the colourless liquid obtained was really water" -
well you could use electrolysis except that'Id be a long method -
and you'Id get hydrogen and oxygen - well I'll write that down
shorten it ? [not clear] - [writes] - well if it is water and it's
just been made it won't be acid or alkali so I 11 probably give
neutral with - universal indicator - that could be another way of
proving it - ’cause it wouldn't have had a chance to mix with any
hydrogen ions - that could have made it go acid - I think we'll write
that down as well - [writes] - I suppose there's a lot of reactions
you could put down - some of them quite way out - like if you put
it in with sodium - it'Id work you'Id get an alkali then - and it'Id
go blue - I suppose if you put down all these tests it's only water
that would give these results - now if I put down that third one
[writes].
2(c) 009 [Reads] "Urea is a covalent compound" - Don't know this
- "try to draw its full structural compound." - [note misreading] -
it must have a nitrogen in the middle because that seems to be its
basic beginning - and that has a valency of four — I think I 11 just
do a little sketch - how we were taught in one year - I'm giving it
four arms to represent one valency [drawing] - erm - each one has two
hydrogens and it says there's two Nl^s so there must be another
nitrogen somewhere - we'll put that on - that must have another two
hydrogens - and - yes well I'm stuck here 'cause there's no-where
to put the carbon - yes I'm stuck — I can't do anything there so
I'll turn over and come back to it.....
3(a) 009 [Reads stem and (a) in full] - well it could liberate the
hydrogen, or the oxygen from the manganese oxide - so I 11 try and
think of an equation for it in my head -
- A20 -
- - ■ \
Ex You can write on the paper if you want to - just .....
009 Yes - I don't want to write it on paper - I'll just think it
out - try and see what compounds could form that would be feasible
in the situation given.
Ex You don't think you've come across this reaction before?
009 No - well I can't remember it - I think the hydrogen is
probably given off - so I'll put that down.
Ex How did you work out that it would be hydrogen?
009 - because manganese(IV) oxide is a relatively stable compound
- but hydrochloric acid - several other things can get the hydrogen
out of its compound - so I put that down as a sort of guess. The
chemical test for hydrogen's the pop test - where you put it in a
cylinder and just lift the lid off and light it and it explodes with
a colourless flame.
Ex How do you remember that hydrogen test? - is that - er you sort
of remember doing it or remember it written down in a book or?
009 Oh - I remember doing it 'cause it was quite vivid the first
time 'cause it exploded completely - so I'll always remember that
- and it's one of those things - explosions seem to stick in my mind
- so put hydrogen pop test with a lighted spill [note he omits word
"lighted" in written answer]..... [Ex encourages].
3(b) 009 [Reads] "Iron sulphide reacts with a dilute acid" - well that'll
give hydrogen sulphide that will -
Ex Well again - how do you know? - not what's the logical reason
for it necessarily but how did you know that was the answer?
009 Because an acid will combine — well - react with a sulphide
and it'll give hydrogen sulphide.
Ex You remember?
- A21
\
009 Yes - 'cause we've recently done it - that's the main reason
why I remember it - [reads] - the chemical test for hydrogen sulphide
- a lot of sulphur compounds - it's either potassium dichromate -
that came into my head first - but I think that's for sulphur oxides
that is - I think it's lead ethanoate paper - and it turns black -
Ex That's fine - that's just what I wanted - good.....
3(c) 009 [Reads] "Ammonium chloride is heated with calcium
hydroxide" - just thing that comes to mind is that calcium hydroxide
is only slightly soluble so that may have something to do with it
- in the end - yes and ammonium chloride is a - sublimes - it will
sublime that will - so the ammonium chloride might not do anything
because it will sublime by itself - the calcium hydroxide may
disassociate - yes - I think that's what happens - I think the
hydroxide gives up its hydrogen — yes I think that's what'll happen
- it'll give up its hydrogen - yes, so I'll put that down - I think
the ammonium chloride will sublime and not react so I'm putting
hydrogen down - no! - it can't be hydrogen because they never give
you the same thing twice! - must be something else -
Ex You seem very certain about that.
009 Yes - quite certain - 'cause over all the past exam papers that
we've done — past questions — they never seem to give you the same
gas twice - they might give you two similar ones but not two the same
- yes - it might be possible that hydrogen chloride could have been
given off - and that would leave.....
Ex That's for c(i)?
009 Yes - we're still on c(i) trying to work out the gas - hydrogen
chloride, the gas not the acid - and that would leave you the calcium
oxide and it'll leave you ammonia - no I don't think we can get a
compound out of that so it must be something else -
- A22 -
009 Yes - 'cause we've recently done it - that's the main reason
why I remember it - [reads] - the chemical test for hydrogen sulphide
- a lot of sulphur compounds - it's either potassium dichromate -
that came into my head first - but I think that's for sulphur oxides
that is - I think it's lead ethanoate paper - and it turns black -
Ex That's fine - that's just what I wanted - good.....
3(c) 009 [Reads] "Ammonium chloride is heated with calcium
hydroxide" - just thing that comes to mind is that calcium hydroxide
is only slightly soluble so that may have something to do with it
- in the end - yes and ammonium chloride is a - sublimes - it will
sublime that will - so the ammonium chloride might not do anything
because it will sublime by itself - the calcium hydroxide may
disassociate - yes - I think that's what happens - I think the
hydroxide gives up its hydrogen - yes I think that's what'll happen
- it'll give up its hydrogen - yes, so I'll put that down - I think
the ammonium chloride will sublime and not react so I'm putting
hydrogen down - no! - it can't be hydrogen because they never give
you the same thing twice! - must be something else -
Ex You seem very certain about that.
009 Yes - quite certain - 'cause over all the past exam papers that
we've done — past questions — they never seem to give you the same
gas twice - they might give you two similar ones but not two the same
- yes - it might be possible that hydrogen chloride could have been
given off - and that would leave.....
Ex That's for c(i)?
009 Yes - we're still on c(i) trying to work out the gas - hydrogen
chloride, the gas not the acid - and that would leave you the calcium
oxide and it'll leave you ammonia - no I don't think we can get a
compound out of that so it must be something else -
Ex What do you mean? - you don't think you can get a compound out
of that? -
009 about the chemicals and elements that are left over.
Ex Well you said ammonia and calcium oxide left over - you decided
you didn't like that did you?
009 No -
Ex Why not?
009 Well, it might be the answer but I think they probably would
have reacted the hydrogen - because one of the hydrogens has gone
off the amomonium - ammonium is nitrogen and four hydrogens but
ammonia's only three - so there's a hydrogen to account for
somewhere -
Ex I can hear the wheels going round - but unfortunately the tape
recorder can't hear what's going on inside so whats?..... you've
obviously heard about it.
009 Yea - I'm thinking whether it could be that - yea - it could
be - I think we'll put that down - hydrogen chloride [writes] - now
I don't really know any chemical test for it but I know it's a white
smokey gas so I'll put that down - yes - one's just come to mind -
its mixed with water it'll give you the acid hydrogen - hydrochloric
acid - so if we tested it with - indicator paper or universal
indicator solution it'll give you a red colour so we'll put that down
[writes] -
3(d) 009 [Reads] "Which of these gases normally reacts as an oxidising
agent" - oxidising - well the only oxidising agent I can think of
at the moment is sulphuric acid - so er - this might be an oxidising
agent - there again it could be hydrogen sulphide - because that is
identical because it also has two hydrogens - like sulphuric acid
- so it's one of those two.
- A23 -
\
Ex Sorry - one of which two?
009 - hydrogen sulphide and hydrogen chloride - it's one of those
two that's the oxidising agent - I think it's likely to be the
hydrogen sulphide actually so I'll just put that down [writes].
4. Now I'll go on to the next question [reads aloud] - "An experiment
was carried out to find the approximate heat of neutralisation
of certain acids with certain alkalis" — the first thing that comes
to mind there's - mixing an acid and an alkali and seeing what
temperatures you get — [goes on reading to the end — then] - well
it's the same molarity so it probably won't involve any maths or
anything like that - first question - [reads] "What is meant by Heat
of Neutralisation?" - yea - that's the heat when an alkali and acid's
mixed together that's given off -
Ex "You're remembering that from a text book or.....
009 Yes - I remember that from a text book that - [long pause -
writing] .
4(b) 009 [Reads] "Why was a container chosen made of plastic?” - well -
glass, that's not a very good insulator really - it can give off a
lot of heat - and it can - have a lot of heat and through it — like
greenhouses can — but plastic - you use that for padding things with
- probably as insulation so no heat's lost [writes] -
Ex Now were you actually thinking that out or did you remember that
this.....
009 no - I was thinking that out because I can't remember along this
experiment, but greenhouses came to mind because they let heat through
and also if you take heat out [unclear]?? you loose a lot...... [Ex
encourages].
- A24 -
MMHBh
4(c) 009 [Reads] "Potassium hydroxide was used" - that's an alkali - the
rise in temperature was exactly the same as in the first experiment -
the first thing that comes there is that nitric acid has the formula
HNOj and hydrochloric acid has the same - has the formula HC1 - and
they've both got one - one hydrogen ion - so that's the same 'cause
heat of neutralisation is caused by the hydrogen ions and the OH ions
being added together - also potassium hydroxide and sodium hydroxide
- they both have the same valency sodium and potassium - so in the
hydroxide there won't be two of them or anything and so it's because
of - there's the number of hydrogen ions and OH ions that there were
in the first experiment that the heat's the same so I'll write that
down [writes] -
4(d) 009 [Reads aloud] - now just having a think about that - because molar
is the same number of hydrogen ions for a given volume or weight -
just reading through the question again -
Ex Which part are you reading through again?
009 - (d) - [reads] - yes - er - not sure what to say here - 'cause
in the above question — I said that hydrochloric and nitric had -
er only one hydrogen in their formula - but sulphuric has two but
it mentions the one molar — which probably means it has the same —
number of hydrogens in all - so I don't know what to put here —
Ex Why don't you know what to put?
009 'Cause hydrogen - if it's 1M that refers to the amount of
hydrogen - in solution - and they're all 1M -
Ex Sounds as if you do know what to put - why are you saying
you don't know what to put? ~ you don't feel sure of it - is that
it?
009 No - I don't feel sure - I'll put there's a more vigorous
reaction - I think - because the one below it is - ethanoic acid or
- A25 -
acetic acid and that is a weak acid that is - so put (i) is a - the
top - the sulphuric is a bit more vigorous reaction and more heat
is given off - [writes] and for the other one I'll put less heat is
given - still not quite sure of that answer but I'll have to.....
[note apparent reluctance to put "no effect" although this is what
he worked out, and that eventual bias against his conclusion is
confirmed by potentially opposite effect in next item]
5. 009 [Reads] Yes - I've just seen the table and its obviously something
to do with - the period 3 probably - of the table.
Ex Why period 3 do you think?
009 Well - because it's taught on the syllabus - that's the first
thing that struck me - the first one's sodium - and that one's third
down so it is [!] - or I think it is at the moment -
Ex Why did you think it was sodium?
009 Because of the mass number and the number of electrons it's
got.
Ex I see.
009 - stick in my mind - no! - it might not [possibly cued to change
mind by Ex's questions?] - could be carbon - a bit confused here -
[re-reads] - it says 7 different neutral atoms - I didn't read the
question there - and er sodium isn't neutral [!] - read the questions
now [does so] "Which atoms are isotopes of the same element? — that
means that they have a different number of neutrons in the - nucleus,
so the changes on them must be the same - because neutrons make no
difference to the - electronic arrangements, so I'll look along the
- number of electrons for two numbers the same — M and Q are 'cause
they're both 18 - they've both got 18 - electrons but they've both
got a different mass number so there must be some neutral particles
in the - in the atom somewhere so I'm putting M and Q down - [writes].
- A26 -
5(b) 009 [Reads] "Which two elements are in the same group of the periodic
table?" - well, there's 8 electrons so - to each - er column of the
er - no group - or the across - I've forgot what it is, but the across
- the periodic table so there'll be - probably - any with more than
8 difference - it'll be an 8 difference I'm looking for - in the mass
number - well it's not 40 and 12 - and it won't be 40 and 19 or 40
and 28 - L, er L M Q and X are the only ones left - so I'm looking
at the number of electrons now - I'm just thinking whether to put
M and Q down again because they're both elements but they're isotopes
of one-another - [Ex and 009 discuss and decide that two different
elements are wanted] - I'm looking at the electrons now for an 8
difference there - because one - must have an ending of 18 so we can't
have that [?] - I think it's probably E and J - I think that's
probably the two but I'm not sure about that - I'll put that down -
Ex Before, you were looking for a difference of 8 in the mass
numbers, now you've gone for a difference of 8 in the electrons -
009 Yes - because I can remember the electron configurations as er
- say sodium's 2, 8, 1 - and all that -
Ex So you think perhaps you were wrong about the mass numbers?
009 Yes -
Ex I see.
009 Yes - so I'm putting E and J down [does so].
5(c) 009 [Reads] "Which element is a halogen - or halogen? [tries two
pronunciations] - That's, that's a minus that is - so it'll have 7
electrons in the outer shell that will - so it'll probably be 2, 8,
and 7, so I'm looking for a 17 there isn't one - yes - it could be
2 and 7 - because that would also be possible - yes, I'm putting down
G 'cause that is 9 - because all hologens have 7 in the outer shell
so I'm putting down G [does so].
- A27 -
5(d) 009 [Reads] "Derive a formula for the compound formed when X reacts
with L" I'm just looking at both of them now - really I think I've
got to determine whether one's a metal - and whether one's a gas or
a halogen or - alkali metal or whatever - or whether it's a transition
element - yes -
Ex What are you thinking now?
009 I'm just looking at it - don't think I'm really thinking at the
moment - I'm just trying to - I think I'll work out the valencies
for both of them - or try to - because then you'll be - because they
might go in a ratio to one another like water does -
Ex OK - you're a bit bogged down with this - let's move on and try
a new question.
009 Yes - yes.....
6(a) 009 [Reads aloud whole item and question (a) without comment] - that's
to make sure all the copper sulphate was reacted [note some pupils
had to re-read several time to sort out what was happening] — because
you'll ruin your crystals if you evaporated the copper sulphate 'cause
you'Id get - a white powder which would be copper sulphate - crystals,
if you evaporated them too much 'cause they loose the water -
Ex time - now you're quite right but you didn't give me any idea
how you know that - you're remembering that from an experiment you
did or? - you probably haven't met this experiment before -
009 No, no - but it just comes to mind that if you don't evaporate
it all - I mean er - dissolve all the iron fillings or react -
whatever you want to use - er you're going to have other crystals
croppipng up.
Ex Oh yes - you're quite right - I was just wondering - you've come
across this word "excess" somewhere before obviously -
009 excess - yes that was in the text a few weeks back that was
yes - a similar question came up then -
- A28
Ex You've answered questions like this before.....
009 Yes.....
Ex ..... and you're probably thinking of - that sort of thing.
009 Yes - so I'm putting down that - that excess needs to be added
so that every bit of the copper sulphate is used - [writes].
Ex Right.
6(b) 009 [Reads] - well it's a precipitation reaction - so - so that means
it's insoluble - ?? (unclear) being formed - I'm just thinking because
it can't be anything like swapping partners - because you'Id be
getting one of the solutions you started with - so it can't be that -
it's an iron compound - because most copper compounds that some to
mind are blue - or white if you take the water out of come of them -
Ex What is it you're looking for?
009 - something to go with it because you wouldn't just get iron
- so I'm just putting iron down - iron - reddish brown - well, rust's
that colour so I think I'll put down iron oxide - for that - because
that's insoluble - so I'm putting iron oxide down -
6(c) 009 [reads] "Which of the substances used acted as an oxidising
agent?" - I'm not sure - I've never been sure of this so I'm not -
so I don't really know quite what to do - [owing to concern with time
and later item on oxidation Ex suggests skipping this part for the
present].
6(d) 009 [Reads aloud] - well - to - iron(II) sulphate - urn -
I don't think it sublimes so there's no danger of that - probably
a poisonous gas is given off or something - er - I'm not sure of this
— it could be a poisonous gas is given off - but then it mentions
a pure product so it might mean that - when the evaporation of the
\
filtrate - is being evaporated - the heat might cause it to react
- I think that's more likely to be it because it mentions a pure
product - it doesn't mention anything about danger, so I'll put that
down [writes] - that the iron(II) sulphate may react on heat - [Reads]
"How might this precaution be taken?" - well if it's anything to do
with heat I think a water bath - might do it - if we put an
evaporating dish in a small beaker and boiled the water underneath
- just leaving a little gap to allow for the pressure - yes I think
that because it won't go above 100° - yes I'll put that down [writes]
— now I've finished that.
6. (e) [Reads aloud] - as I mentioned before copper sulphate can lose its
water - so I think that's probably why - if the crystals have lost
their water and become anhydrous - 'cause water weighs quite a bit
- yes, I think I'll put that down - [writes].
7. 009 [reads] "Define oxidation in terms of changes at the atomic level"
— oxidation — I'm not sure of this at all — what oxidation is — this
one's going to be a hard question - ......
Ex Well, what would you do if you met it in your 0-levels?"
009 I don't know - really - I 'Id probably just have a go at it but
they probably wouldn't be very good answers, because - probably rush
it - and try and get off it so I can have a better go at another
question — or go back to another — [decides with Ex to go on to 8
and 9 and return if time at the end].
8. (a) 009 [Reads] "Give the name of the compound present in pure soap" -
pure soap, that's the stearate ion that is - 'cause I remember that
— I've got no particular reason for it, I just remember it — well
I think I remember it - I may have confused it with something - but
it's got something to do with hard water.
- A30 -
Ex No - soap certainly contains stearate ions - you're right.
8(b) 009 [Reads aloud] "Explain why soap will not lather with hard water”.
- it's because of - I think it's magnesium ions in the water - yes
I think that's why [writes] - don't think I can give a good reason
for it.
Ex You just know it's something to do with magnesium?
009 Yes - I know it's something to do with magnesium - I don't
think I can give a better reason for it.
Ex Is that from discussing it in class or from reading a book
or..... ?
009 No - it just sticks in my mind - a certaian page of a book and
it's got that on - or something like that -
Ex Let's just go back to 8(a) a minute -
009 8a - yes.
Ex It says give the name of a compound present in soap - are you
quite satisfied with your answer there?
009 Yes - I think that's probably right -
Ex Well - the answer's right, but do you think the stearate ion is
a compound?
009 - no it isn't - it's a - ah - ..... when I was thinking of it
before sodium came into my mind — so I think I'll put sodium stearate
and cross out the ion.
Ex That's fine - I wonder why that happened?
009 I — I wouldn't have - if you hadn't have told me, I 'Id have left
it — but sodium did go through my mind at the beginning but I just
didn't write it down [or refer to it!] - it shot through my mind....
Ex Why do you think you settled for stearate ion - which would
probably get half the mark - rather than sodium stearate - you just
didn't notice they'd asked for a compound or......?
- A31
009 I think it's because I didn't - I just wished the question -
present in pure soap - something - that's probably what went in -
that's what I wrote -
8 (c) 009 [Reads aloud] - well they're all basically the same thing - the
first thing that comes to mind is that sodium hydrogencarbonate might
dissociate on heating - and the hydrated sodium carbonate would
probably just - stay - yes I think I'll put that down - because sodium
carbonate's just chalk - and it just goes brown on heating - I think
it would dissociate on heating sodium hydrogen carbonate -
[writes].....
Ex Where did that idea come from do you think?
009 - because it's got the hydrogen in there and I think the heat
would probably make it lose that - but I know sodium carbonate when
you heat doesn't do anything so I'm putting that down - [goes on
writing] - yes, now I'm going to 9(a).
9(a) 009 [Reads] "Name the hydroncarbon series of which propene is a
member" - well - it says hydroncarbon, hydrocarbon series - so it's
either an alkene, alkane or alkyne - and it ends with ENE so it must
be an alkene this one -
9(b) 009 [Reads aloud] I'll draw - I'll draw in three hydrogen - three
carbons — alkene means it has double bonds, so I'll put in a double
bond between each of the hydrogens - carbons - [drawing] and er -
that - that just - oh that's wrong that is 'cause I've drawn one too
many [bonds on a carbon] - these two have got five - so I'll cross
them off [hydrogens from end carbons] and I'll put a hydrogen on each
of those - there - that's what I'll do [adds Hs to middle carbon]
- because I've drawn the carbons first because it says then
- A32
9(c)(1)
9(c)(ii)
9(d)(1)
9(d)(ii)
I just put the double bonds in 'cause It's an alkene -
009 [Reads aloud] - don't really know..... [propene Is not strictly
in syllabus so when 009 stuck Ex asks same question re ethene,
which is in the syllabus] - well it's - organic compound - to start
with - I think it could be bleach actually - but I'm not sure about
that - but I think I'Id put bleach - [Ex steps in and gives correct
answer which is needed for subsequent parts - 009 immediately
recognises] - oh aye yes -
QQ9 [Reads aloud] - well, I don't think it's catalytic cracking -
actually - as you only use that to get liquids and gases - and
polythene's a solid - could be a chain reaction - 'cause it is a
polymer polythene — don't know what made me think that — but I think
it probably is - no, I can't remember exactly how polythene is made
- just thinking then, about nylon how we made nylon - if it's made
like that - by two liquids being together and the two surfaces
meeting — you hook nylon out - I just wondered if it's anything like
that - no I can't think of anything - no - I can't think of anything
I'll just put polythene is a polymer and that might get something
- for that [writes]..... - you can only lose out by leaving blanks.
009 [Reads aloud] - well its name describes what it is - hydrogen
and carbon — it's a compound consisting of those two elements.
Ex Yes - do you remember that from your notebooks or.....
009 - just sticks in my mind that does [writes]......
009 [Reads aloud] - no it isn't - polythene isn't - as it doesn't
consist of - hydrogen and carbon - so I've put no — there. [009
now volunteers to have a go at question which was missed out].
- A33
\
7(a)
7(b)
7(c)(1)
7(c)(ii)
009 [Reads aloud] - this may -it's something to do with gaining
oxygen - and losing hydrogen I think so I'll put that - [writes] -
something is gaining oxygen -
Ex What do you think this bit about changes at the atomic level
means?
009 - I don't know what that means - at all - so I'll just sort
of try to bluff my way through and ignore it - 'cause I don't
quite know what it means -
009 [Reads aloud] - oxidised - oh, I said it was gaining oxygens -
there's no oxygen here - so it must be losing hydrogen - except
there isn't hydrogen in number 2 - yes - I think I'll underline
bromine in number 2 and hydrogen in number 1 as a guess - 'cause it's
a sort of pot luck thing.
009 [Reads aloud] - well that's where it gains a valency - gains -
more than one valency that does - the sulphur. Name the industrial
process - no - can't think of that -
009 [Reads aloud] - no - brings nothing to mind that doesn't either -
Ex What happens when nitrogen's turned into ammonia?
009 It gains hydrogen.
Ex Yes - do you remember that as an important industrial process?
- turning nitrogen from the atmosphere.....
009 No.
Ex ..... into ammonia?
009 No - in the mocks I didn't revise this - 'cause I don't like
the subject at all 'cause I don't remember it very well.....
TAPE ENDS
- A34
PUPIL 010 - TRANSCRIBED PROTOCOL (Test 03)
1(a) 010 [Reads to herself] - [laughs] we've just done this in chemistry
..... - at the anode it's - the electrolysis of water -so - at the
- anode I think it's hydrogen and at the cathode oxygen - or vice
versa [laughs] - [Ex asks how she obtains this answer] - I can
remember writing it down - 'cause we didn't do it as an experiment.
Ex I see - ..... it's a matter of sorting out which way round it is
then?
010 Yes - I think it's at the anode it was hydrogen - urn [Ex
instructs to write answer(s) as in a "proper" test].
1(b) 010 [Reads to herself] - a 1:2 ratio is expected because - being the
electrolysis of water there is twice as much hydrogen in water than
there is oxygen - so when you - electrolyse twice as much hydrogen
— is expected to be given off — [looks to Ex for confirmation — Ex
explains that she must not expect this - 0 1 0 writes answer silently].
[Ex asks to indicate when she reads/writes].
l(b)(ii) 010 [Reads aloud quietly] - [Ex queries silence and asks what she
is thinking] -
010 - I'm not thinking of anything! - urn - if - if the electrolysis
is done in water the hydrogen and oxygen will dissolve a certain
amount — therefore — they'll dissolve at different rates — so the
same amount isn't — obtained as it should be.
Ex Now where does that idea come from — does it just seem the most
likely - or is it something you've discussed?
0 1 0 - seems the most likely -
Ex I see — which one do you think would dissolve most?
0 1 0 - the oxygen -
Ex Again why? - why have you gone for that one?
0 1 0 Well - in water fish breath oxygen - and not hydrogen - [laughs]
- and quite a lot must be dissolved - so - write it in. [Does so
without reference to which dissolves most!].
l(c)(i) 010 [Reads under her breath] -
Ex Right, again can you..... it doesn't come naturally to think aloud
I know.
010 No - um - increase in concentration - I should think more gas is
given off because - um - because there'd be - oh God - [Ex tries to
encourage to explain thoughts and not just give answers].
010 I don't know if it's right - it's just a guess - cause I'm not
sure - I don't know I ' Id leave that one - is that OK? [Agreed to
skip after a try if she would do so in a real test].
l(c)(ii) 010 [Reads under her breath] - it would be warmer so - er - um I don't
really know that one either.
Ex [Not wishing to discourage] OK - try part (d).
1(d) 010 [Reads silently] - oh - um - conduction of electricity is the
movement of electrons — so — in a copper wire the electrons are being
pushed round whereas in sulphuric acid - there - ions - and ions and
things in the liquid so - current comes to - er -
Ex Now what are you doing there?
0 1 0 - trying to work out which way the current's going.
Ex So you've drawn a little circuit with a cell.
010 Yes cathode - anode - goes to positive to negative - so it - the
current will go to the cathode first - em — and the sulphuric acid s
changed to — produces ions which then are attracted to the — anode
- positive ions - which are attracted to the anode - and then carry
on right through so there's electrons - no - doesn't make sense.
- A36 -
1
2(a)
I-
2 (b)
2 (b)(1 )
Ex No - you've offering it to me instead of - instead of trying to
put it on the paper [tries to encourage and suggests she re-reads the
question and tries to pin down her answer].
010 [Re-reads] - X know the bit about the copper wire - cause I know
about that one - urn - [long pause] - in the dilute one I'd just - the
sulphuric acid - I think I'ld - like what I said [laughs] -
Ex Well OK - you're getting a bit bogged down - [explains that she
has all the necessary ideas and that all that is needed is reference
to charge being carried by electrons in a wire and ions in an
electrolyte - tries to encourage].
010 Oh 1 see..... I thought they'Id want more than - that though
you see [Ex continues to try to encourage - notes also that she
seemed to have trouble trying to decide how to express answer for
what was wanted — suggests tries to start the thinking aloud
process by saying what the question means to her as she reads it
what it seems to be asking for].
010 [Reads aloud] - so - valency for ammonium is one - carbonate is
2 - carbonate's C03 - so that's NH - um - ammonium gas is NH^ so itl'd
NHj - NH - HN3 twice - C03 [writes using brackets correctly] .
010 [Reads aloud] -
010 [Reads aloud] -
Ex [at once] "Can you tell me what that seems to be asking you for
- what are you trying to do?"
0 1 0 Um - how you'Id prove the solution produced is water - in any
experiment - more so than just this actual one - um - oh gosh
Ex Now, what are you trying to do? Are you trying to remember all
the tests you can think of? - or are you trying to think of an
experiment where you had water to test or?.....
- A37
010 I'm trying to think of the sort of things that water actually
does -
Ex Yes.
0 1 0 Um - [unclear] - ..... that it puts out a flame - and - [writes]
puts out a flame - um [interruption while Ex shuts window to cut down
noise] - don't really know -
Ex OK - well how about part (ii)?
2(b)(ii) 010 [Reads silently] - Huh [emphatic!] - I'm a disaster at these!
- (Ex encourages to have a try) - not really sure what it wants here
- if it's like when you draw a structure for - er - in - er - organic
chemistry? - [Ex confirms] - oh dear - [agree to abandon to 010's
obvious relief].
3(a) 010 [Reads silently] -
0 1 0 [under her breath]..... useless at acids as well - [laughs - Ex
encourages] - concentrated - that means something - the fact that
it's concentrated rather than dilute - erm - can I write out the
equation?
Ex Oh yes - do any writing you like.
010 er - [sighs] Mg - [writes Mg02 + HC1 MgCl + ] - er - I thought
it might be chlorine - [unclear] - I mean manganese chloride - but it
can’t be 'cause there's no gas given off 'cause it would leave water -
er -
Ex You thought it would be chlorine you say?
010 - Manganese - chloride - but it can't be because there's no gas
left - there's an H and 02 - which means it'Id be water - um - H -
Ex What about part (b) - part (b)'s a more familiar one perhaps.
3(b) 010 [Reads] - oh dear -
- A38 -
M tM H h
Ex This one's a laboratory preparation.
0 1 0 - I think it would be hydrogen chlor' - um hydrogen sulphide -
Ex That's right - how did you get there?
010 Well - er - hydrochloric acid so there'Id be some hydrogen - and
it's sulphide - ion(II) sulphide - so - sort of first thing that comes
to your notice -
Ex I see — well — fine•
010 I'll write that in [does so] - um - test - when we were making
it - er - we did it with - was it lead ethanoate - or something
and we were told you could do it with paper but we hadn't got the
paper so we used the ? [unclear] - [writing] lead ethanoate, paper
- I think it turns a bluey-grey -
Ex Do you - are you remembering this colour from being told it
or.....
010 No - from when we actually did it - and we procured the solution
in - it turned a metallic bluey-grey - [Ex confirms and encourages
further after answer written out].
3(c) 010 [Read sotto voce] - erm - I think it might be - ammonia - because
ammonium compounds normally release ammonia - huh - [Ex reminds that
he should not be looked to for confirmation - but does confirm to
encourage her this time!] - [writes ammonia] - oh gosh - I think it s
an alkaline gas which is unusual - most of them are acids - so it
turns - blue litmus paper red [writes] -
Ex Now how do you remember which way round it is for litmus - blue
to red - red to blue?
0 1 0 I can always remember ac' [hesitates] - acid turns it red to
blue.....
[Ex Gives answer to 3a and on basis of 010’s reaction skips 3d and
passes on to 4].
- A39
4. 010 [Reads silently] -
Ex Have you got to (a) yet?
010 No - I'm just reading it again [does so] - now I can remember
doing this - not long ago -
Ex What - doing the experiment?
010 Er yes - erm - heat of neutralisation - that's either the heat
that's produced or taken in during a neutralisation - and urn - have
to think of another way of saying it - er -
Ex Now what are you thinking?
010 Just reading it through again - ..... _ urn - think I'Id just
write the - heat [writing] either needed - no taken in or produced
during reaction - erm -
4(b) 010 [Reads quietly] - plastic container - urn - thinking what he told
us — cause Mr Thorne told us this - ..... er - think it's because
it doesn't take in much heat - from the actual experiment and
therefore - the reading on the thermometer would be much more accurate
- yes - I think that's - em [writes and speaks] because it does not
absorb much heat from reaction - er (c).
4(c) 010 [Reads silently) - er - just reading the first bit again - well
they're both the same volumes that are added to each other — so it
probably has something to do with that — and it's the same molarity
in both as well - erm - I think that's probably what it is - erm -
[v. softly] - [got to?] write that down - [writes] - ..... same -
same volumes is used — and the molarity of all the solutions is equal
- er (d).
4(d) 010 [Reads silently] - erm - what would happen [under her breadth]
Ex You're reading it again?
010 Urm [affirmative] - I'm not sure if I understand this actually
- A40
- what would happen to the measured rise in temperature if the first
experiment was repeated — oh yes — that's better — erm — don t really
know - uh - erm - was thinking it might be that sulphuric acid is
a strong acid - but it's not - I don't think - erm — .... . - don t
really know - [reading (ii)] ethanoic - I know that's one of the
weaker acids - so maybe not as much heat is produced - because erm
- it won't react as much - I'll write that down - erm — [writes]
- acid - [writes only "weaker acid so does not react as much ].
5. 010 [Reads silently] - neutral atoms - [mutters] - oh that’ll
probably mean it doesn’t have a charge wont't it? - neutral - erm
- [talks under her breath while looking at the question] - number
of electrons and the mass number — er — mass numbers protons plus
neutrons - and number of electrons is equal to number of protons -
[reading v. softly] - use the letter at the top of a column to
represent the element - or one atom of element - [re-reads in a
whisper].
5(a) 010 Oh I see - um - which atoms are isotopes of the same element
erm - well isotopes have the same number of protons - that means
there'll be the same number of electrons - that's M and Q.
5(b) 010_ [Reads aloud] - well - um - er - I think you work that out by
doing the - electronic structure - and it's the last number in the
electronic structure - s o 6 is 2 - 4 , 9 is - 2 , 4 - 6 - 9 er 3 - 14
is 2, 4, 4, 8 , 10 - no it’s not it's 2 - 2, 4 - 6 - [whispers] -
[that's] 8 - 2 , 4, 8 - 2 - 2 - that'll be 7 - er - oh I don't think2
there's a 4 in it, is there? - equations' 2 n - so - the second is
..... [rubs out some of pencil working before Ex can stop her] -
that'll be 2, 4 because there are 4 electrons - this'll be 2 - 7
- A41
this one will be 2, 8 - 4 - this'll be 2, 8 , 10, 6 - this'll be 2,
8 , 8 - 2, 8 , 8 - [long pause] 2, 8 , 8 , 1 I think - I'm not certain
about that - urn - I think it's E and J because they've got the same
last number - so I think I'll write that down - E and J -
Ex You say it's the same last number - is - this - I mean, have you
done a question like this before and you're just remembering a rule
o r .....
010 Er - I haven't done one exactly like this but - I think that's
what we were told but I can't be certain — ...... [Ex encourages
again].....
5(c) 010 [Reads aloud] - don't know what a halogen is - em -
Ex But you said the word right and you read it quite confidently
so it's not a new word is it?
010 No - I've heard of it - erm - [mutter] - I think it might be
something to do with organic chemistry -
Ex Well, let me tell you the name of one of the halogen family
chlorine is the best known of them.
010 Oh - it’s the group on the periodic table -
Ex Right.
0 1 0 erm - chlorine - that's got a number of 1 2 I think - I think it's
E - I think chlorine's got a - er - erm - I don't know what it's
called - in the periodic table - it’s got a little number underneath
it - I think that's 12 - but I'm not certain - and there's one here
with 12 - so I'll write E down - [little laugh].
5(d) 010 Reads under her breath] - X and L
Ex You've circled those on the table — so you can keep track of
them.....
- A42 -
\
010 Yes - um - oh dear - erm - L needs 2 electrons to represent -
or become like its nearest - stable gas - and X needs to lose 1 -
no - six - no it needs to lose - two - that means [unclear] add one
- 'cause it's all back to front 'cause it's minuses - erm - got to
think - different erm - don't really know this - [Ex encourages] -
I think - it would be X2L - that's twice because that needs to need
one - you can have twice as many molecules of X - as L so I'll write
that down - X2L ..... [Ex directs to last page].
7. 010 [Reads aloud] - um - just done this and I can't remember it -
erm - oxidation is the addition of oxygen - the taking away of
hydrogen - erm - oh dear - um - trying to remember what he wrote on
the blackboard and I can't remember - [Ex asks about the definitions
already given] - Yes - we've done a lot of those - yes - throughout
this school and - then we were told some more and I can't think what
it was - [owing to shortage of time Ex reminds 010 that oxidation is
loss of electrons — she agrees she now remembers this — so she can
attempt the next part] -
7(b) 010 [Reads softly] - iron plus hydrogen - that's iron because it'sI 1 + ,
the addition of hydrogen - so underline that - [underlines Fe J
- copper - [mutters] - copper plus - tch - did you say looses an
electron?..... [Ex confirms] - copper's loosing two..... that'll
be copper because it's lost two electrons to become positively charged
- right (c).
7(c) 010 [Reads half aloud] - oh dear - don't think I know these.
Ex Well, you may know them by other names- sulphur(IV) oxide and
sulphur(VI) oxide
0 1 0 - that'll be S0 2 ah - and that'll be SO3 - well it's clicking
- A43 -
now. I've heard of those two - sulphur dioxide is - - and
that'll be sulphur trioxide but I don't think I've heard of that -
um - no I don't think I know it - I'll leave it - [reads part (ii)
half aloud] - I think that's the Bosch process - but I'm not certain
- um - catalytic reduction - I think the Bosch process is the only
one I can remember so I'll write that one down.
Ex Yes - how did you get the Bosch process?
010 Well - it's - I can remember it in my book and it's where you
add - hydrogen and nitrogen together — the two elements to get it
- and I think there's another one - a process to make ammonia but
I can't think what it is -
8 (a) 010 Name a compound - oh that's er - sodium, or potassium, stearate
because we've done that in needlework. I'l put sodium down 'cause
I'm not so sure - [brief asides on needlework]..... [writes answer].
8 (b) 010 [Reads aloud] - oh - I can remember doing this as well - in
chemistry - something to do with the fact that the water's got calcium
in it - and I don't think it reacts very well - that's the only thing
I can remember — I'll just write that down - [writes].
Ex You can remember this from your roles, or from discussing it in
class or..... ?
0 1 0 I can remember it in my notes - the fact that it contains
calcium something or the other — I always forget it I 1 1 write that
bit down - I don't know what the rest of it is - there's something
else as well - anyway (c).
8 (c) 010 [Reads under her breath] - sodium - oh we've just done this before
I came in [laughs] - er I didn't do it though - I know it now - em
I think sodium hydrogencarbonate decomposes on heating to give
hydrogen - and releases the hyd' -..... the sodium carbonate - and the
- sodium carbonate doesn't release it - is it hydrogen or is it carbon
dioxide? - oh dear -
Ex How will you sort it out?
0 1 0 -[mock tearfully!] I don't know! - oh it annoys me this ---
Ex I can hear the wheels going round - what are you trying to do?
010 Trying to remember - think it must be hydrogen because - it's
the only thing really because if it's carbon dioxide the sodium would
give it up as well probably - so I'll write hydrogen [writing] -
hydrogen is given - [completes writing silently].
9(a) 010 [Reads under her breath] - propene - means that it's got a double
bond - that's C double dash C [writes -C = C-] think it's alkene -
[Ex confirms] - that'll do - alkane is the single bond.
9(b) 010 [Reads quickly to herself] - propane - you have CC - must be
another one like that - won't want two double bonds I don't think -
6 — carbon's got a valency of 4 and you've used up 2 there [010 is
drawing a structure as she speaks] - that would be 2, 3, 4 — yes
you've only used up one there — 1, 2, 3, 4 that's it — um — H, H, H,
one, two, three, four - one two.
Ex More artistic - sort of at an angle.
010 - he said - Mr Thorne just said something about it goes at about
120° 'cause it spreads itself out - right 1, 2, 3, 4, 5, 6 — it's
the right numbers.
Ex [Encouragingly] It's the right answer too!.....
9(c) 010 [Reads half-aloud] .
Ex Well it would be fairer to ask you from the syllabus - if we said
it for ethene - 'cause ethene's in the syllabus.
- A45 -
010 Urn - it might be ethanol or propanol because that's an alcohol
- II ' 1 1 write that down - an alcohol - don't know what it's called -
9(c)(i) 010 [Reads aloud] - hm - might be an addition of something - propanol
Ex Why did you say addition?
010 Well to make it something had to be added or taken away - and
- I should think it might be the addition - of something -
Ex You don't know why you preferred addition to subtraction? -
010 No - I don't know.....
TAPE ENDS
PUPIL Oil - TRANSCRIBED PROTOCOL (TEST 03)
1 (a) Oil [Reads aloud] Dilute acid - em - so that's electrolysis of water
- I remember doing that - and hydrogen and oxygen are evolved - anode,
that's positive so - hydrogen ions are positive, oxygen ions are
negative so hydrogen's given off at the anode - and - er - oxygen at
the cathode - so er - [Ex reminds Oil to write in his answers] - the
gas formed at the anode, hydrogen - er no no no - ? [unclear] - oxygen
at the anode - hydrogen - cations - at the cathode -
1 (b)(1 ) Oil [Reads aloud] - er - because the formula's 1^0 - so there's two
hydrogen atoms to every one oxygen - so I'll write that down - [writes
- confirms in answer to Ex that answer arises at once from knowing
that H 2 0 is electrolysed] .
[Ex discusses this answer - Oil states that he would express his
answer more fully in an actual examination answer but not otherwise
add to it. On being told he was making an assumption he referred
to Avogadro's law (though not by name) but felt it unnecessary to
mention this - he noted space allowed seemed to limit what was
wanted].
Kb)(ii) Oil [Reads aloud] - that's solubility - I remember doing something
on this question - I think oxygen's more soluble so I'll write that
down [does so - speaking aloud] "oxygen has a greater solubility than
hydrogen at the same temperature so more oxygen is dissolved in the
remaining water".
!(c)(i) Oil [Reads aloud] - well erm - concentrated sulphuric acid - the more
concentated you get, it prevents the electrolysis — I think
something like that. You start - you start electrolysing sulphuric
acid - so er - I'll have to put that down - in a sentence but - here
- A4 7
goes - [writing] "this has the effect of slowing the electrolysis
of water" - it's more ions or something - I'm not sure of that.
l(c)(ii) Oil [Reads aloud] - well if the temperature's increased that would
increase the temperature of the water as well - er - that makes the
solubility greater - erm - whether it has any effect on the
electrolysis I don't know -
Ex The solubility of what?
Oil The solubility of both - hydrogen and - oxygen - so - I can't
think of anything that affects it apart from that so - so I'll put
that down [writes] "the solubility of the gases evolved will be
increased" - it might make the sulphuric acid more active or - or
likely - could make the ions more easy to electrolyse - I don't know
really -
1(d) O U [Reads aloud] Well, in a wire there are electrons - a sea of
electrons free - they flow once you push more in - in an acid it's
carried by the - er - by the ions - sulphate ions and hydrogen ions
- or the er - the hydroxide and hydrogen ions in the water so er - ?
[unclear] - that er -[writing] "there is a sea of electrons in copper
wire which carry the current, but ions in the solution convey the
current".
[Ex discusses the question and Oil says he has seen it before although
some time ago — he simply remembers answers to (b)(ii) and (d) for
example ] .
2(a) O U [Reads aloud] Well, ammonium NH^ - I know that - carbonate -
carbonate's got a double valency so it's NH^ two - CO^ - yeh - I think
that's right.
2(b)(i)
2(b)(ii)
Oil [Reads aloud] - erm - I could test the water - react - water turns
cobalt chloride paper - I think it's from pink to blue - well it
hydrates the anyhydrous copper sulphate - er so - it's either one of
the two - ? [unclear] a test for water - I'll put that down [writes]
"water turns dry cobalt paper blue". I think that's the right way
round.
Oil [Reads aloud] - er - it's full structural formula - (NH2>2CO -
erm - well I'll start of with the carbon - there's the C - I've got
one of them [writes] -
Ex Why start off with the carbon do you think?
Oil Well - it's the basis - there's 4 bonds - like if you're working
with just hydrogen - after that you add the hydrogens onto the carbon
Ex It's experience with other formulae is it - .....
Oil Yes.....
Ex ..... that you're basing it on perhaps?
Oil Yes - that's just the way 1 do it - I'll put the carbon down
'cause it's got the most valencies - erm - NH2 - now er - I think
they go down as er - one - I'm not sure but - I can t think of
anything else - I've never met it before - carbon's there - I seem
to remember urea having a double bond somewhere but - ? [unclear]
is two — two bonds - no — can't think of anything else NH2
[mutters] - I think that's wrong but - no idea on that really [starts
to turn over].
Ex You've come across urea before? - it didn’t sound to be a strange
name to you.
Oil No - er - done it in biology - but it's a different - ? [unclear]
of properties from the [mutter].
- A49 -
\
3(a) Oil [Reads aloud] - um - only one guess(?) - two(?) - oxides
manganese(IV) oxide is it - [mutters]...... reducing agent.....think
it might be - name of the gas - well it' s MnO - MnC>2 - and HC1 - you
get water formed [mutters]..... is it oxygen given off there
somewhere - think that's the - oh - gas you might get given off -
oxygen there seems to be a lot of oxygen - there - MnC^ - so I 11
put oxygen [does so] - chemical test - don't know if relighting a
glowing spill's a chemical test but - it's a physical test - oxygen
- don't know any chemical test - I'll just see if they accept that
[writes] "relights a glowing spill".
3(b) 0U_ [Reads aloud] - ah - I think that’s hydrogen sulphide - sulphides
give off hydrogen sulphide so - [writes] hydrogen sulphide .
Ex Now there did you actually remember it as soon as you saw sulphide
Oil Yes.....
Ex or were you swapping over hydrogen's and ions and sulphurs and
so on?
Oil No - no I never bothered about that - I saw iron(II) sulphide
and I thought if there's a gas given off it'll be hydrogen sulphide
- chemical test - from memory - I remember it - I think it's lead
acetate paper - hydrogen sulphide - um - it's either that - yes
[writes] "turns lead acetate in solution" - I'll put solution
black".
Ex Now fine - you're spot on but you had a little bit of doubt about
that - when you were thinking around that - were you thinking of other
chemical tests you knew about ~ .... .
Oil Yes.....
Ex ..... and seeing which matched up with the hydrogen sulphide
or.....
- A50 -
\
oil Yes - sulphur dioxide - I was getting the two mixed up - which
one was lead acetate and which was p o t a s s i u m . •
Ex No - I wondered if you were sort of checking properties of - of
hydrogen sulphide or checking on tests you knew.....
Oil Well, I thought it was an oxidising - reducing agent or an
oxidising agent - ? [unclear] work it out - em - so I didn't think
on that - no I just - knew one was lead acetate - and - thought it
was obviously hydrogen sulphide.
3(c) Oil [Reads aloud] - ammonium chloride - hm - you get calcium chloride
- [mutters] - don't know which gas given off there so - calcium
chloride - ammonium hydroxide - ? [unclear] ammonium - there'Id be
two ammonium chlorides [appears to be trying to compile an equation
in his head] - 'cause ? [unclear] - yes - there'll be ammonium
hydroxide and then ammonia given off - er - can't think of any other
gas - can you? - chlorine may be - that's a possibility - but I ?
[unclear] calcium chloride - so ammonium - ammonia [writes] - anyway
chemical test for ammonia - well it's an alkali gas - turns red litmus
blue - I think - I think - I'm not sure - I don't know any other test
for it so - [writes] - turns red - moist red litmus blue.
3(d) O U [Reads aloud] - urn - well I've got oxygen down there - and if
that doesn't act as an oxidising agent well - hydrogen sulphide
erm - well that takes oxygen away - can't give anything so er - ?
[unclear] that'll be a reducing agent so er - yes well oxygen seems
content(?) - oxygen [writes] - hope it's the right answer.....
Ex Right - let me just check a couple of things - what do you use
for the laboratory preparation of ammonia?
Oil Erm - any chloride er - any er - ammonium salt and a strong base
- like - alkali - it's ammonium chloride and calcium hydroxide I
think.
- A51
■ n!! \
Ex I see - yes.
Oil Ammonium chloride and calcium hydroxide [reading] - oh yes - so
ammonia would be given off there I should think -
Ex Uh - uh - so you might have met that reaction as a lab preparation?
Oil Yes -
Ex You didn't recognise it?
Oil I didn't realise that - no I just..... [Ex encourages] - taken
it from the context actually - you know - didn't cotton on that they
were preparations - .....
Ex One more thing - in (d) it says "which of the gases will react
as oxidising agents? You checked the answer to (a) and decided
oxygen was OK - you checked the answer to part (b) - you never checked
the ammonia - or you never said anything about checking it - did you
consider you'ld already done it 'cause you'd got an answer?
Oil Well - I thought em - I might - I just checking hydrogen sulphide
because - I knew that was one or the other - well X thought it was
- I then I didn't bother with (c) - it was a waste of time really
if oxygen is there — 'cause oxgen's definitely an oxidising agent
- by its name - [further questions by Ex establish that Oil assumed
the item required only one gas].
4(a) O U [Reads aloud] erm - right - heat evolved - it's an exothermic
reaction - amount of heat given out ? [unclear] - er - um one mole
reacting to neutralise one mole - [mutter] - there’s definitely heat
given out when an acid is neutalised by an alkali - don t know whether
there's any specific volumes required - not going to put it if I don t
know it -anyway [writes] "it is the heat evolved" - I think it's
evolved - I don't think there's heat taken in - "when an acid is
neutralised by an alkali or vice versa" - check that - heat of
neutralisation - well I've come across that but X can't remember what
it was so - I'll have to leave it I think.
- A52 -
4(b) Oil [Reads aloud] - hydrochloric acid you've put into - a beaker
erm - oh yes - because plastic's a good insulator and won't - take -
er - the heat - can't see any other reason.
Ex That's fine as an answer - where did it come from do you think?
Oil Well - er - think it's from memory more than anything - I
remember doing it and.....
Ex You've done an experiment like this?
Oil Yes - we've done an experiment like it so - at the time we'd done
- we'd done it in a plastic beaker because of heat - and then looking
at question (a) - heat of neutralisation - I knew it was something to
do with heat - so er - the second question's obviously related
to that heat - and it seems the obvious answer - to cut it down -
so [writing] "because the plastic is a better insulator so less heat
is lost" - now (c).
4(c) Oil [Reads aloud] potassium hydroxide and sodium hydroxide - erm
well er - yes um - the same volumes react - I don't know why - I
should think it was because the same volumes reacted - and
neutralisation - that er - same heat is given off per volume
something like that - ? [unclear] actually reacted - don't really
know - rise in temperture exactly the same as in the first experiment
- molar nitric acid - potassium hydroxide - erm - "the heat evolved
[writing] "is the same because the same volume of acid and alkali
reacted and were neutralised" - not really sure on that but er
um - don't know. I've come across that so I'll have to leave that
and hope - (d).
4(d) Oil [Reads aloud] erm - oh - now in that case it's something to do
with hydrogen ions - erm - so question (c) - something about the same
- A53
\
amount of hydrogen ions - [writes, adding to his answer to (c)] "the
same amount - number of hydrogen ions reacted" - I think that's right
- I'm not sure but - I'll leave it anyway. What will happen to the
measured rise in temperature - sulphuric acid - well there's two
hydrogen ions - erm - well if there's two - I think there's either
going to be double or a half - erm - not sure ? [unclear] - I think
it'Id be double - 'cause there's twice as many - proportional to
the hydrogen ions - [writes] "the rise would be doubled - twice as
much" number (ii) IM ethanoic acid - CH3COOH - um - well there's 4
hydrogen ions there altogether but - whether they're all - part of
the acid - I think probably H3 is part of the acid - er reacting as
an acid. I'm not sure on that I've never come across it before.
[Ex reassures that it's not strictly in the syllabus] Yes well I
think just the hydrogen in the CH3's the part we're interested in
- um - I'm not sure but it seems that way anyway - so I'd say the
- if it's the same as number (i) - the rise would be triple [writes
this]. I'm hoping that number (i)'s right.
5. O U [Reads aloud] "neutral atoms" - um - number of electrons [looking
at table] — and the mass numbers — number of electrons 6, mass number
12 - oh yes 9, 19 - [continues reading question] - so the mass
number's the protons and neutrons - erm - now (a)
5(a) O U [Reads aloud] - which atoms are isotopes? - that's different
neutron content - so er - same number of electrons and therefore
protons - 6, 9, 14, 16, 18, 18 ah - H and Q - which atoms? M and Q.
5(b) Oil [Reads aloud] - it goes up in 7s and 8s - there's 7 groups - ?
[unclear] - 6 and 3 are 9 - erm - 9 and 7 - 1 6 - 1 6 , 18, 18, 19 er
- A54 -
\
- urn - in the same group of the periodic table - right, could be
double that - 6 - 14 [mutters] - 6 and 7 - 6 and 7 - 13 - or it could
be 6 and 8 - 1 think they may go up in 8s - the last question I met
- something like that - so I'll say 6 and 8 - add 8 onto all of the
others - 9 and 8 - 17 - there's not one like that - so I'll say E
and L [does he mean E and J?] because ? [unclear] any others - E and
L [writes them] - (c).
5(c) Oil [Reads aloud] - halogen - group 7 - so er that would be - 1, 2,
- , 2, 3, 4, 5, 6, 7, 8 - 8 electrons I think - if you count hydrogen
as one and 2, 3 (?) - I think it's got 8 - 8 - there's more with 8
- 16 would be L - that would mean that - 6 would be - erm - [note
- has previously put E, 6 electrons and L, 16, as being in the same
group ] - if you took away 7 - ? [unclear] seven - call it J - but?
doesn’t ? ? [unclear] (b)(?) but I can't do - I can’t see the
difference there so er - obviously L isn't 'cause that would mean
E was - and it's only one element so er - [mutters] - I think 14
electrons - 7 groups - 9 , 2 [very softly - muttering] -
Ex Now - what are you counting now?
Oil I'm trying to work out er - the - periodic table - how many
different sets there are - I'm not sure - I thought it was 7 but it's
more - I think - I don't think it is J so er - I'm going to put 9
because I think 9 - and then 8 - and that agrees(?) with (b) and so
- they're either both wrong or - they're both wrong! - (d).
5(d) O U [Reads aloud] When X reacts with L - derive a formula for the
compound - erm - now they want how many (?) bonds I suppose - X2L
- something like that - 16 electrons - 2, on 8 - that's 10 - so
that'Id be 2 - it'll have a valency of 2 [looking at L] - X er - 2,
A55 -
and 8 and 8 - 16 - yeh - it’ll have a valency of 1 - is it 2 - 8,
1 0 - 8 , [mutters] - I think it does - looks like it does - em - X 2L
- probably wrong - hope so.
Ex Can I just come back to a couple there - you went for G in the
end, did you on number (c) ? Can you explain how you got there?
Oil Well er - I -thinking back on the periodic table I think there's
H out on its own - hydrogen on its own - and er then you've got the
group I - group II - and the sort of first one in group I - will have
er - 2 electrons - and er - if it is 8 across - 8 different group
across - then it must b e l + 8 - 9 - 9 electrons so.
Ex - the hologens are off at the end are they - the right hand end?
Oil Yes.
Ex I see - yes OK.....
Oil Group 7, the halogens I think - oh yes - I thought the halogens
were the last group — don't know if they're the last or the
penultimate — I'll leave it as that.
6(a) Oil [Reads aloud] - iron with an acid - is it with an acid? - erm
copper(II) sulphate - no acid - erm - oh yes - to make sure there’s
no impure - so's all the copper(II) sulphate will have reached - so
- [writes] "all the available copper(II) sulphate will react - to
make sure I'll put [adds this] -
Ex Now again - how did you get that - you're familiar with this word
excess?
Oil Yes - it's usually - with - acids - because then you don't get
concentrated acid - so I thought if you had iron filings you could
filter those off easy enough - and then you're left with - er -
whatever - there's no copper(II) sulphate - very dilate solution left
- so I just replaced acid with copper(II) sulphate basically - .....
- A56 -
6(b) Oil [Reads aloud] - erm - filtered off - well we’re trying to get
iron(II) sulphate - erm - [rereads] "..... the mixture was filtered"
- [goes back again] "an excess of iron filings a little at a time
..... to a solution of copper(II) sulphate - yes copper sulphate.
Ex You're writing an equation?
Oil Yes - I'm writing it down 'cause - iron - ? [unclear] rust(?)
get iron sulphate - that stands to reason - plus copper - that's
what? [unclear] anyway now [has written CuSO^ + Fe FeSO^ + Cul -
[reads] "a reddish brown precipitate was formed and the mixture was
filtered" - ah ? [unclear] iron(II) sulphate then -
[writes]..... write iron(II) sulphate down - I think that's right
- [however re-reads (b)] "before the mixture was filtered - give
the name of the substance which had to be filtered — oh — the name
of the substance which had to be filtered off - er — yes — not liquid
so it's not iron(II) sulphate - if it's filtered off it's the left
overs so it's - the er - copper - I misread the question there.....
[alters answer].
6(c) O U [Reads aloud] - iron(II) sulphate ? [unclear] - oxidising agent
- er - sulphates are negative - so er - the iron itself is reduced
so the copper acts as an oxidising agent - yes that - er - iron
iron takes the sulphate - so iron is reduced - and oxidising agents
are reduced - so er - which of the substances used acts as an
oxidising agent - erm - iron - I think that's right anyway 'cause
they've only given you a little space to write it in
6(d) O U [Reads aloud] - nature of iron(II) sulphate - special precaution
had to be taken during evaporation - iron(II) sulphate - erm - it
decomposes or someth' — or dissociates — I don t know what the nature
of iron(II) sulphate is but - I should think it'll be something like
- A57 -
that - erm - it'll react - what do you think this precaution might
be - the filtrate was evaporated taking all necessary precautions -
erm - [mutters under his breath] - I think it - I haven't a clue -
er might decompose if it's heated strongly - I think that's the only
one I can think it might be so er - case of elimination - that's the
only one I can think of so - what do you think the precaution might
be - "not to heat too strongly" [writes] "thus preventing - thermal
dissociation" erm - I don't know about that.
Ex What do you get if iron(II) sulphate does dissociate because of
the heat?
Oil erm - iron(II) sulphate -
Ex I'm just trying to check up - do you know that it dissociates
or.....
Oil No I don't - I don't know - I think it's iron(III)chloride that
does something - whether it goes to iron(II) or not I don't know but
- just guessing that bit - whether it reacts to form iron(XII)
sulphate - I don't know - there's quite a lot about being oxidised
and a reducing agent - erm - whether it will form iron(III) sulphate
- I don't know - I don't think so - no - I'm not sure on that one
at all -I'll just leave it as it is -
6(d)(ii) Oil [Reads aloud twice] - um - that seems to indicate that it's not
going to be thermal dissociation - erm - um - what else could it do
- react with oxygen? - um - ? [unclear] - um - how might this
precaution be taken - hm - by leaving it to evaporate in the window
I should think - ? [unclear] I don't know - [writes] "leaving it to
evaporate at room temperature .....
6(e) O U [Reads aloud] - back to the parts I don't know really - er - every
care - crystals - so - somethng obviouisly happens - some of its got
to decompose or - ? [unclear] react again - erm - actual yield and
calculated yield - er - I don't really know - despite every care -
mass of crystals - much less than that calculated from the balanced
equation - well obviously ? [unclear] from the equation - molar
solution of copper(II) sulphate - doesn't say but
Ex Would you know to calculate the yield? - ..... if you were given
the atomic masses for example?
Oil - ? [unclear] work out the equation and then find how many moles
per mole and then er - ? [unclear].
Ex You probably would be able to.
Oil Actually I don't really know any answer to that [it is agreed
to move on - time being short].
7(a) Oil [Reads aloud] - [reads again] - that means its electron structure
- erm - there's an increase in valency - decrease in valency
oxidation - oxidation is the er - decrease of electron
electronegative particles ? [unclear] atomic level - hm - I think
so - the loss of electrons or - decrease - I think so - I ’ll put that
- "decrease [writes] in the electronegative constituent" - urn - the
electronegative constituents go down - then er - there s oxidised
- yeh - I think that's right - I don't know whether that's what they
want -
Ex How do you remember which way round it is? You know,
electronegative going down for oxidation and up for reduction.....
Oil er -
Ex Do you have any special way to remember which way round it is?
Oil - well no - X just er -I thought it was decrease - of er - say
just take iron sulphate - if you take away the electronegative which
is the sulphate - em - that's oxidising the iron so er - the iron's
oxidised - that’s oxidation so er - it’s a decrease because you lost
- A59 -
- the er sulphate - so there's more iron - that's the way I think
it out - work it out but -
7(b)
Ex Fine -
[ | j | |Oil [Reads aloud] - substance which is being oxidised - Fe to Fe
- iron(III) to iron(II) - iron(II) is oxidised to iron(III) - so it
must be reduced to iron(II) - erm - so it must be H - H to H - em -
increase in electrons - if it loses an electron it becomes positive
- loss of electrons - that could be the answer to (a) - I don't know
I'll leave it at that - or loss or electrons - I'd better tack that
on at the end - er - is it - I mix the two up - the loss of an
electron - H - loses an electron - becomes - so the iron gains the
electron - now electrons are considered to be negative so yeah -
I think that’s right [forgets to add to previous answer (a) re loss
of electrons] - copper plus bromine - copper two to - plus er - ions
- so the copper's been electrolysed there - and it's bromine is a
reducing agent - er oxidising agent - er it gains an electron
increasing the negative - I think that's right - ? [unclear] [has
underlined Cu]•
7(c) Oil [Reads stem aloud] - industrial processes ~
7(c)(i) Oil [Reads aloud] - industrial processes - em - catalytic reduction
of nitrogen to ammonia [this is part (ii)] - that the Haber process.
Ex You're remembering that from your notes or - text book or
what.....
Oil Yes - ? [unclear] writing it down -..... I don't know the first
one - never came across it so -
Ex What other name might you have for sulphur(IV) oxide and sulphur
(VI) oxide - they've probably got more familiar names.
- A60 -
Oil Sulphur(IV) oxide and sulphur(VI) oxide - sulphur dioxide and
sulphur trioxide - catalytic oxidation - sulphur dioxide to sulphur
trioxide - well that's in the making of - er - this - er contact -
er - it's either contact or addition - contact's something to do
with er - sulphuric acid - and that's something to do with it - the
contact - the contact process - well it's better than nothing anyway
[writes] - I remember doing something.
Ex It's a lot better than nothing - it's right.
Oil Yes well - yes - it just came through my head - it's sulphur
dioxide - sulphur tri there so - .....
8(a) Oil [Reads aloud] - oh er - T - er D , T , T er - T er - the name of
a compound present in pure soap - date - steardite - star - oh oh
- stearate that's it - sodium stearate [writes stearate only].
8(b) Oil [Reads aloud] - I should know this - er soap reacts - with the
er - calcium carbonate and so forms a scum - something like that
the er - soap [writing] reacts with the calcium carbonate - forming
a scum - [mutter]..... better explanation than that - I can't think
of one though so I'll have to leave that — ••••••
TAPE ENDS
- A61
PUPIL 012 - TRANSCRIBED PROTOCOL (TEST 03)
1(a) 012 [Reads to herself] - well I know It's as It is in water - and
_ h+ - 0_ - so - anode's positive, cathode's negative - so hydrogen
at the cathode and - and oxygen at the anode - is that alright?
[Ex confrims all going well and encourages etc].
Ex You said straight away that this was the electrolysis of water
- erm - what made you think that?
012 Well - we did the experiment with dilute sulphuric acid - I can
remember from that.....
1(b)(1) 012 [Reads to herself] - a 1:2 ratio is expected because - water is
in the ratio - is H20 - and so the hydrogen will be double the oxygen
ratio - [writes silently] -
Ex OK - let me ask you another bit then - this means, according to
your explanation, which is fine, every time you get an atom of oxygen
given off at one electrode you get two atoms of hydrogen given off
at the other - and you're using this to explain the fact that - there
are two volumes - there's twice the volume of hydrogen that there is
oxygen - erm - you seem to be making an assumption there that — well
- hydrogen atoms and oxygen atoms are the same size [expands a little
on this] -
012 Well volume of gas is the same - well - it's 2.4 litres at ST
- 22.4 litres at STP - [further discussions suggests that 012 does
not seem to think this is a necessary part of the answer].
l(b)(ii) 012 Now I'm just reading [does so silently] -
Ex Now you must have had time to read that and you're mulling it over
- can you - try and let us know what you're thinking even if it's
not getting you anywhere? -
A62 -
\
012 Well I just thought - perhaps - the apparatus Isn't very ?
[unclear] - experimental error - apparatus leaks and things like that
- perhaps it's that - yes - experimental error -
Ex But you're obviously not altogether happy with that as an answer.
012 No - it doesn't really seem - [laughs] - well - yes - I can't
think of anything else -
Ex I see - so you'Id go for that? -
012 Yes - ..... [writes] [note Ex's interference may well have
curtailed 012's effort at this answer!].....
1(c) 012 [Reads silently] - if you increase - the concentration of the
sulphuric acid - there'Id be more and more water lost - though the
hydrogen given off and the oxygen given off - I don't honestly
understand the question -
Ex Well - what don't you understand about it?
012 Well, if the current is kept constant - what would be the effect
of (i) increasing the concentration of the sulphuric acid - if the
current was kept constant - the concentration of sulphuric acid would
increase anyway - so - pointless question -
Ex Why does that make it pointless? -
012 Well - well I just - .... - oh I see - less hydrogen and oxygen
will be given off as there'Id be less atoms - fewer atoms - I
understand it now - sorry -.it’s if - when you're adding more
concentrated sulphuric acid to ? [unclear] already em all right
- the rate of the reaction would increase - [Ex asks 012 not to refer
her answer to him for approval to proceed as in a test]. [012 writes
her answer].
I l(c)(ii) 012 - and increasing the temperature of the sulphuric acid - I don t
- it wouldn't change the rate of the reaction
- A63 -
■
Ex OK - well write that in - but then see if you can tell me - how
you got to that, because we had quite a pause before that came out-
012 [Writes] - well, we didn't do an experiment to show that when
you heated it didn't - the temperature didn't increase - and the
electrodes - will er - it's all to do with concentration rather than
heat - 'cause the electrodes are placed in the sulphuric acid
Ex OK - fine - you can't think of any reason why it should make any
difference?
012 No - not really at the moment -
Ex No - you’re quite right - I'm just trying to get at how you're
thinking about it - OK you're reading part (d).
1(d) 012 [Reads silently] - sulphuric acid contains ions whereas copper
wire contains electrons - or electrons which - move around - when
the electricity’s passed through them -
Ex Again - we got a confident answer very quickly - have you
remembered this from.....
012 Yes - er not the text book - notes - it's sort of part of you
know she stresses it very strongly - ..... [writes]......
2(a) 012 [Reads aloud - without prompting to do so]. Well ammonium's got
a valency of 1 and carbonate's got a valency of - two - so it's NH4
COj - two minus so it's NH4+ twice [writes as she speaks] - yes.
2(b)(1) 012 [Reads aloud] well you could - erm - anhydrous copper - sulphate
- put the water on it and it will turn back to its - hyd - on the
hydrated copper - sulphate - which is white - put water on - if the
liquid was water it would turn back to blue - or you could use cobalt
chloride paper - which turns from blue to pink when water's present
- I'm just writing it down - [does so].
A64
2(b)(ii) 012 [Reads aloud] - [sighs] - I'm not very sure about this so - [Ex
encourages to have a go] - um -
Ex Well - we're having a pause again - are you thinking over how you
might tackle it?
012 Yes - I thought just of - say - like organic chemistry - where
you have little arms - but then I - I discarded that - because I think
it means with all the electrons on and the - free - electrons - and
I'm not very sure about doing that - those anyway - (Ex explains that
only the "arms" are wanted!] - ..... oh well - perhaps I can try that
- erm - ..... starting from the back now 'cause I know C and 0 have
a valency of two - and therefore they'll have two arms joining them
together - so I'm just drawing that —
Ex You say you know that - how do you know it? -
012 Well - I'm - it's common knowledge.
Ex You've seen it lots of times like that have you?
012 Well, I know carbons got a val - oxygen's got a valency of two
and carbon - and carbon dioxide's written with two - a linear formula
..... _ nh - er - well - I think that means that N in the middle and
two arms to the Hs on the end so I'll try that [drawing] - now I've
got to join them together - carbon's got four arms - a valency of
four - because erm - carbon dioxide's writen with two arms coming
out - well — shall I show? -
Ex No - I know what you mean anyway -
012 - [mutters] -
Ex Now what are you muttering to yourself now?
012 I was just em - trying to think now of some way to join the two
together - two arms floating aroud - and nitrogen's got a valency
of - three - and I've only accounted for two - but in here it's
got - it’s got to be two of those - so if I join one of those to there
- A65 -
mmmmm
- and then draw another - ..... would you like another
version?..... [agrees with Ex to leave diagram as it is; at first
Hhad written =C=0 and I; then added bond from N to C and further NH^
NiH groups]..... [Ex encourages].
3(a) 012 [Reads just audibly] - well we did this - I can remember doing
this - it was at the beginning of my fourth book - so the name of
it's - chlorine.
Ex OK - you said you can remember doing it - and then there's quite
a pause before the chlorine came out - you were just.....
012 Yes - .....
Ex You knew you knew it but you couldn't actually remember the name
for a minute or what?
012 No - I looked at the oxide and thought for a minute - I had a
mental block and thought - ? [unclear] it's oxygen you see - 'cause
of manganese(IV) oxide but - I think it - yes it is chlorine - I'm
writing that down - and the chemical test - er blue litmus paper turns
from - goes to red - showing it's an acidic gas - and then it bleaches
- I'm just writing that down - I can remember that because - when we
did the actual experiment we had to test for the gas - and I can
remember the actual - .....
3(b) 012 [Reads aloud] - well I'm not very sure about sulphides and
sulphites I always get them mixed up - but it's with hydrochloric acid
so there's H+ ions around - so I'll guess and say it was H2S - and
and the chemical test - lead ethanoate paper turns from brown to white
- no turns from white to brown - -
- A66 -
Ex Again - how did you remember the test? -
012 Well - it's partly the teaching because we always have little
quick snap tests at the end of a - thing..... [agrees with Ex that
it is memorised].
3(c) 012 [Reads aloud] - hm - well when ammonium chloride's heated it -
dissociation occurs - calcium hydroxide - hm -
Ex I can almost hear the wheels going round but can't hear it on the
tape.
012 Sorry -..... just thought of ammonium hydroxide - and calcium
chloride - but - I don't think - I don't know the chemical test for
a gas and I don't think it's on the syllabus so - ? [unclear] - so
I - ammonia - so I'll have to write ammonia down..... and the
chemical test for ammonia - well I don't know the chemical test ~
but I know that when it's mixed with hydrogen chloride it'll - gas
- a white - thing forms which is - ammonium chloride - so urn - I've
forgotten the chemical test - oh well it's got a very strong smell -
no -
Ex You're thinking of things you know about ammonia?
012 Urm -
Ex What's wrong with the hydrogen chloride one as a chemical test?
- Why did you reject that?
012 Well I haven't seen it done in a lab' - I've only seen it done
in a physics lesson - rather - and it doesn't seem very probable as
a chemical test — they're usually a bit simpler -
Ex I see.
012 It's usually something like bleaching or something like that
Ex Yes - you've done preparation of ammonia in the lab' have you?
Ex Yes..... in the lab' - how did you prepare it in the lab'?
- A67
012 Oh em — we have not — we haven't done it in the lab we ve just
just done it - in the Haber process.
Ex I see - you haven't done a way of getting it in the lab ?
012 There's that - it's got calcium oxide as a drying agent and
I'm just trying to think of it — ammonium chloride —
Ex Yes - and why did you think of the drying agent first?
012 Well er because - er - I can remember the drawing - and the big
tower - drying tower with the calcium oxide - .....
Ex Was this on the board or in the text book ?
012 In my book - I can remember most of the things from my book you
see -
Ex Your book? - you mean your notebook? -
012 Yes - an ammonium compound - calcium compound - yes it is ammonia
produced - I still don't know the chemical test..... [Ex and 012 agree
to move on to the next part].
3(d) 012 [Reads aloud] Well we're just been doing oxidation and reduction
- and redox actions - and chlorine's a halogen - and that - is reduced
when it reacts or something - so I would say that’s the oxidising
agent - ..... [012 starts to read 4].
Ex Hang on - you seem to have been quite satisfied at just finding
one that's an oxidising agent - is that OK?
012 Oh which - oh sorry - which of these gases, so perhaps it's more
than one..... coming to think of it H2S - yes - I can remember a
reaction - I can't remember the formula but I can remember H2S is
in it..... [Ex stops and assures that chlorine is the only one but
was interested in how the question was interpreted]••••••I just
1 misread the question you see..... [agree in conversation that more
than one gas might have been involved, and pass on].
- A68 -
V
4. 012 [Reads aloud] That's the heat produced when an acid is neutralised
by an alkali - [writes this] - and as that doesn't seem a very full
explanation I'd better put a bit more in - I'll put OH ions are
neutralised - are - when H+ ions are added to OH ions - to form HjO
[writes equation] - can't think of anything else -
Ex Now why did you think your answer needed to be made longer?
012 Well - you left three lines and I usually - have to write more
than - three lines if my answers to - you know - to get decent marks
in the exam say - I find that when I write little short answers
they're wrong -
4(b) 012 [Reads aloud] - well, in order to find the temperature properly
you'Id need to insulate it - and plastic's a good insulator - and
could be - just accounted as part of the insulation instead of a glass
beaker stood -
Ex Again - where did that idea come from?
012 Well - we did it in Physics you see - we did - it doesn't have
to - well - we did an experiment where - we were finding the heat
??? [unclear] the heat capacity of water and there we used a plastic
beaker - but there again it could be something to do with the fact
that - well I don't - react with glass or anything - so it couldn't
be anything like that - ? [unclear] - so I'll put down - about how
it’s insulating - [writes answer].
4(c) 012 [Reads aloud] - um - well - oh yes - nitric acid and hydrochloric
acid - both - strong acids - and potassium hydroxide and sodium
hydroxide are um - well - hydroxides and they're strong - alkalis
- and therefore the numbers of ions involved are exactly the same
- and so the rise in temperature will also be the same
Ex Yes - that's the right answer - again - how did you get there?
- A69
It came very quickly - obviously you didn't have any trouble thinking
it out.
012 - Well we've done quite a few of these examples before - and they
always seem to be - well sort of the same - you know - why - the same
- and it's all to do with strong acids and weak acids -
Ex Yes - OK fine - ..... [012 writes answer].
4(d) 012 [Reads aloud] well sulphuric acid's also a strong acid and so
- the temp' - the rise in temperature would be the same - ethanoic
acid - acetic - acetic acid's a weak acid - and therefore it's got
a fewer number of fully dissociated ions - and therefore - there'Id
be fewer than can combine with - the sodium hydroxide - and so I'Id
say the heat of neutralisation would drop - ? [unclear] I'll write
that in [does so] ..... [Ex encourages].
5. 012 [Reads aloud including all parts] - isotopes of the same element
- isotopes — the same number of protons but a different number of
neutrons - mass — number of electrons — that's equals number of
protons — and the mass numbers the number of protons take - away
the mass number — so isotopes of the same element - will have the
same number of electrons and M and Q have the same number of
electrons — and so M and Q are isotopes — and they have different
- er mass numbers — [mutters] — I'll just think it out again -
isotopes — the same number of protons but a different number of
neutrons - mass numbers the number of protons and number of neutrons
- number of electrons is equal to the number of — protons - yes
I - and also chlorine - is - has a mass number of 35.5 and 37.5
- but each is 17 - I can remember that from when we did another
exam' paper - so I'll say it's M and Q -
- A70 -
5(b) 012 [Reads aloud again]..... Well a period of the periodic table
is the line across - and the group is downwards - um - as there are
8 across the periodic table it'll go up by 8 - I've got to find
somewhere - assuming ? [unclear] this is right - mass number will
increase by 8 - [mutters as she looks at mass numbers] - J and M -
5(c) 012 [Reads aloud again] - oh - halogens - that's chlorine, iodine
and bromine - in things like that - hydrogen, helium, lithium,
beryllium, boron, carbon, nitrogen, fluorine - so that's 10 - 8 - I 11
have to say M again -
Ex Where did the 10 come from?
012 Hydrogen, helium, lithium, beryllium, boron, carbon, nitrogen,
oxygen, fluorine - so it's 9 rather than 10 - so it's not M [counted
on her fingers] - nine - it's G [Ex queries how the 10 led to M]
..... well - I knew there's 8 elements across in the periodic table
- so 10 and 8 - well there was no reason why it couldn't have been
Q actually -.....
5(d) 012 [Reads aloud again] [012 circles X and L on the table] - number
of electrons in the outer shell of L - is - shall I write it down
here - 2 - 8 and 6 [Ex asks why she is doing this] ..... well er
- it's to find - it's to find the valency first - by how many ions
it -..... [Ex encourages] - 2 - 8 - now 8 and 1 - so - X has got
a valency of 1 and L has got a valency of 2
Ex Why 2?
012 6 - and it needs two more electrons to make it up to 8 which is
the inert gas configuration - and that needs to lose 1 electron
make it - one - so - therefore that - that’s the first one - so it's
^ 2 “Ex You said that's the first one - what were you talking about there.
012 Well I was thinking that - that was the metal
Ex Yes -
- A71
6(a) 012 [Reads aloud] erm - an excess of iron filings? - to make sure
that all the sulphite ions - sulphate ions in the copper reacted
- with the iron - otherwise you'Id still have copper(II) sulphate
which couldn't be separated from the iron - I'm going to write that
in [does so].
Ex Now presumably you weren't working that out for the first time.
012 No - we've done this before - a very similar one..... - now.
6(b) 012 [Reads aloud] - ah, now I go back to the thing -
crystals prepared - little at a time with stirring to a solution -
reddish brown - well it's iron sulphate - iron and copper sulphate
- hm - I'll just read it again to make it more clear - crystals of
iron(II) sulphate - iron filings were added a little at a time with
stirring - so a solution of copper(II) sulphate in water - a reddish
brown precipitate was formed - yes that's right - so the mixture was
filtered off - well - you're trying to form iron sulphate - and
therefore - must be - something other than iron sulphate - the only
thing that is there is - copper and water - and they don't react
- um - -
Ex What are you thinking now?
012 I'm just - it doesn't really - click in my head.
I'm trying to think of a reddish brown precipitate - I can think
of iron - the iron oxide - but you want to get rid of the copper -
I don't - I'm reading it through again - ? - I'm just underlining to
draw attention to them [underlines key words - see script] - so I've
got iron filings - copper(II) sulphate - and I'm trying to make iron
sulphate so I can cross out the sulphate — they ve got to b_ copper
and water and they don't react - so - I don't really know what it 11
be - name of the substance - I'Id say it was copper oh yes it
is copper [confidently all of a sudden] - erm - displacement reaction
- [Ex discusses her reasoning]..... well it was a reddish brown I -
I'm used to, you know, pink - rather than reddish brown.....
6(c) 012 [Reads aloud] - well oxidation is - addition of oxygen - loss of
hydrogen - and it's a loss of electron - so I'll write down the
reaction I think - just to make it clear to me - I won't bother to
balance it - well I might - [laughs] - it’s iron(II) so - [writes
Fe + CuSo^— ^ FeSO^ + Cu] - Cu two plus, so minus, Fe two plusses -
I'll say it's erm - addition of oxygen - loss of hydrogen - I'll say
the iron - is used - as an oxidising agent - but it wasn't reduced
- perhaps it was - ? [unclear] - Fe becomes Fe two plus - that's
Fe's got a full outer shell - Fe two plus - urn I'll just have to wor'
- Fe - minus two electrons - yes it's - I'll say the iron - as - it s
been reduced because there's been the addition of electrons - s o
l'll put - I'll leave that and perhaps I'll come back -
Ex You're not altogether happy with that?
012 No -
6(d) 012 [Reads aloud] - hm - ? [unclear] I'm trying to think - what
vague patterns of iron(II) sulphate do - I'm not very familiar with
it - as it - I don't even know the colour actually - I think it s
- I think I can remember someone saying about how it's meant to be
- yellow - and and - or something and it then turns green - ?
[unclear]- perhaps that's got something to do with it - or perhaps
it's just a different substance altogether - hm - er - it's sulphate
so it’s not likely to become sulphite on heating - ? [unclear] highly
unlike - urn - I don't really - you know - I don't think - OK -
couldn't do (ii) either [abandons reluctantly].
- A73 -
■
6(e) 012 [Reads aloud] - [Ex assures that this unrelated to the precautions
referred to in previous part] - ..... . - perhaps the calculated yield
doesn't - take into account the pressures of the - atmosphere in
the room - I don't think that's got anything to do with it -
Ex That would mean it was a bad calculation I would think.
012 Yes - erm - actual yield - calculated yield — urn — I'm now looking
at the things here -
Ex Do you know what's meant by calculated yield?
012 - with molar equations and -
Ex OK - you do know.
012 - perhaps they didn't take into account the water in the crystal
- if there is one(?) - yes perhaps it - I can't think of anything
else so I'll put that down - [writes].
7(a) 012 [Reads aloud] - erm - well I know the definition of oxidisation
is - loss of electrons, loss of hydrogen and addition of oxygen -
but at the atomic level it's to do with atoms - atoms and electrons
- and so it's - an atom which loses electrons to become an ion — yes
- I'll write that - and define it in slightly more - [writes] -
[Ex reassures that there is excess room for the answer in this case].
- I'm not too sure about the atomic though - I'm thinking - about
whether — I should put down about loss of hydrogen and addition of
oxygen - but loss of hydrogen's the same as loss of electrons — I 11
just leave it — perhaps I'll - I usually — in the exam' I'Id put it
in because if I'm not sure I put in as much as I can and hope for
the best. [Ex confirms she can leave it as it is in this case] .
7(b) 017 [Reads aloud] - FeJ plus hydrogen gives Fe plus H - well I've
just said that - an atom - oxidisation is an atom which loses an
electron to become the ion - and I know - it must be reduced -
- A74
Ex What must be reduced?
012 The iron's being reduced - and the hydrogen's being oxidised -
so - hydrogen's being oxidised - I'm having second thoughts - .....
Fe3+ gives Fe2+ - I'll have to write it down - and losing electrons3+- taking them away - so Fe minus an electron - Fe three -.....
3+ v 2+[writes Fe - e — ^ Fe ] -
Ex Will you try to say what you're thinking -
012 FeJ - if you take an electron away from that - it becomes Fe
it's - rather than the hydrogen that's being oxidised - it'll be -
the hydrogen is the oxidising agent - and the iron is being oxidised
- I’m still not very sure — erm — I'll leave that for a moment and
go on to the next one - [reads equation (ii) aloud] - oh - halogens
are - oxidising agents - therefore they're being reduced, therefore
the copper's being oxidised - ...... I always get it mixed up - Cu -
actually - I'll go into the realms of electrons - electron
configurations - so that's got a full shell — which you could take
away electrons from that — gives an ion - and therefore definitely
- that's being oxidised - the Cu [underlines Cu] - and I'll come back
to this one now - the Cu - the hydrogen's being - it's usually -
hydrogen - hydrogen is a reducing - of course - hydrogen is addition
- reduction - addition of hydrogen, loss of - oxygen - addition of
electrons - so that the hydrogen is the reducing agent - therefore
Fe+ is being oxidised - no that's being reduced - oh gosh [whispers]
- therefore - oh - it's hard to be logical. [Ex encourages].....
Fe3* - Fe2+ - oh gosh - it's 50:50 either way isn’t it! [Item
abandoned in disgust, but see immediately below!].
7(a)(i) 012 [Reads aloud then reads part (ii) aloud] - industrial process
that's the Haber process - [writes] - oxidation of sulphur(IV)
well it says here oxidation of sulphur to - sulphur(IV) to sulphur(IV)
- A75 -
m
Ex What must be reduced?
012 The iron's being reduced - and the hydrogen's being oxidised -
so - hydrogen's being oxidised - I'm having second thoughts - .....
pe3+ gives Fe2+ - I'll have to write it down - and losing electrons3+- taking them away - so Fe minus an electron - Fe three -.....
3+ . 2+[writes Fe - e — ^ Fe ] -
Ex Will you try to say what you're thinking -O I 2 *f"
012 FeJ - if you take an electron away from that - it becomes Fe
it's - rather than the hydrogen that's being oxidised - it'll be -
the hydrogen is the oxidising agent - and the iron is being oxidised
- I'm still not very sure - erm - I'll leave that for a moment and
go on to the next one - [reads equation (ii) aloud] - oh - halogens
are - oxidising agents - therefore they're being reduced, therefore
the copper's being oxidised - ...... I always get it mixed up - Cu -
actually - I'll go into the realms of electrons - electron
configurations — so that's got a full shell - which you could take
away electrons from that - gives an ion — and therefore definitely
- that's being oxidised - the Cu [underlines Cu] - and I'll come back
to this one now - the Cu - the hydrogen's being - it's usually —
hydrogen - hydrogen is a reducing - of course - hydrogen is addition
- reduction - addition of hydrogen, loss of - oxygen - addition of
electrons - so that the hydrogen is the reducing agent - therefore
Fe+ is being oxidised - no that's being reduced - oh gosh [whispers]
- therefore - oh - it's hard to be logical. [Ex encourages].....
Fe3+ - Fe2+ - oh gosh - it's 50:50 either way isn't it! [Item
abandoned in disgust, but see immediately below!].
7(a)(i) 012 [Reads aloud then reads part (ii) aloud] - industrial process
that's the Haber process - [writes] - oxidation of sulphur(IV)
well it says here oxidation of sulphur to - sulphur(IV) to sulphur(IV)
- A75
so I can apply that - to their - that quest - that (b) - sulphur(IV)
oxide - sulphur(VI) oxide - that's got 4 elect - 4 to 6 - and that's
3 to - so I'll put the hydrogen is being oxidised in that question
- I'll put the hydrogen is being oxidised in that question - I'll
go back to this now - no I don't know that one
Ex Do you know - can you put a name to sulphur(IV) oxide and
sulphur(VI) oxide? - more common names -
012 No -
Ex What about formulae?
0^2 — S — sorry — yes — sulphur dioxide to sulphur trioxide —
Ex Does that help you to think of the industrial process?
012 Urn - oh dear - I could name what the catalyst is - and what the
temperature is and things but - ?
Ex Do you remember what industry uses it?
012 Em - sulphuric acid - we've used - urn - yes when the sulphur
trioxide's mixed with water if forms sulphuric acid - um - well
we've been through it but I can't -
8(a) 012 [Reads aloud] - sodium stearate - ..... [states that this was
remembered from notebook in reply to Ex's question].
8(b) 012 [Reads aloud] - hard water - it could mean temporarily hard water
or permanently hard water - temporarily hard water's got - erm -
calcium ions in - which react with the sodium at - calcium - calcium
sulphate and magnesium sulphate - and er - so the sodium stearate
- swops partners as well - sodium goes onto the - and calcium stearate
- calcium stearate is formed and that's insoluble - so I’ll write
that down - [starts doing so] -
Ex Again the reason's fine - but have you worked it out now or are
you more or less remembering it?
- A76 -
so I can apply that - to their - that quest - that (b) - sulphur(IV)
oxide - sulphur(VI) oxide - that’s got 4 elect - 4 to 6 - and that's
3 to - so I'll put the hydrogen is being oxidised in that question
- I'll put the hydrogen is being oxidised in that question - I'll
go back to this now - no I don't know that one
Ex Do you know - can you put a name to sulphur(IV) oxide and
sulphur(VI) oxide? - more common names -
012 No -
Ex What about formulae?
012 - S - sorry - yes - sulphur dioxide to sulphur trioxide -
Ex Does that help you to think of the industrial process?
012 Um - oh dear - I could name what the catalyst is - and what the
temperature is and things but - ?
Ex Do you remember what industry uses it?
012 Em - sulphuric acid - we've used - um - yes when the sulphur
trioxide's mixed with water if forms sulphuric acid - um - well
we*ve been through it but I can’t —
8(a) 012 [Reads aloud] - sodium stearate - ..... [states that this was
remembered from notebook in reply to Ex's question].
8(b) 012 [Reads aloud] - hard water - it could mean temporarily hard water
or permanently hard water - temporarily hard water s got erm
calcium ions in - which react with the sodium at - calcium - calcium
sulphate and magnesium sulphate - and er - so the sodium stearate
- swops partners as well - sodium goes onto the - and calcium stearate
- calcium stearate is formed and that's insoluble - so I'll write
that down - [starts doing so] -
Ex Again the reason's fine - but have you worked it out now or are
you more or less remembering it?
- A76 -
012 I can remember it - [writes].
8(c) 012 [Reads aloud] - well - em - I'm thinking of carbonates and it s
drummed into us that all carbonates decompose on heating except sodium
and potassium - and - if these decompose when they're in the form
of hydrogen carbonate - so - I would heat them - and hydrogen would
be produced - with the sodium hydrogen carbonate hydrogen would be
produced which you could test by - um - a lighted spill - and hydrated
sodium carbonate - nothing would happen - so - the test wouldn't work
- so I’d write that down - [does so].
9(a) 012 [Reads aloud] "of which propene is a member" - well propene
CH - prop - it's alkenes because of the - ene at the end - .....
[writes].
9(b) 012 [Reads aloud] - Oh - enes - alkenes - alkanes are the - alkenes
are the double bond - between the - carbons and therefore - like that
- [draws C = C = C] - 3 C's and 6 H's and each carbon's got 4 bonds -
H H H1 I I
[has drawn C = C = C]I ) IH H H
9(c) 012 [Reads aloud] - um -
Ex Well - in a way it's not fair 'cause propene isn't in your syllabus
- what if it was ethene? That is in your syllabus......
Ex - make ethane or ethanol - I suppose you could make propanol -
TAPE ENDS
- A77
PUPIL 013 - TRANSCRIBED PROTOCOL (TEST 03)
1 . 013 [Reads silently] - [on querying Ex finds 013 reads right through
to part (d) silently] - going back to 1 (a) - and - don't know if we've
done this but don't know the answer - I should guess one of the gases
would be hydrogen - er - hydrogen's positive - er - the anode’s
positive and the cathode’s negative - so I would guess ano - cathode s
- hydrogen given off -
Ex Yes - now you said you think hydrogen's one of them - where do
you think you got that idea from?
013 - Well - mostly - out of electrolysis we've done, hydrogen's been
given out _
Ex I see - yes - so it's on the basis of experience.
013 Yes - another gas - well formula's - hydrochloric acid's H,,S04 -
I should guess oxygen - at the anode
Ex Now again - you got the answers right so you're doing fine - but
- why did you guess oxygen? - because it was H 2 S0 4 - because there’s
S there as well as 0? -
0 1 3 well - there’s a lot of 0 there - and it's a good guess
Ex More of it than anything else - [013 nods] - you didn't think
of sulphur dioxide for example as a possibility?
013 No - ....Ex You weren't influenced by this 1:2 ratio which you'd read about
later on in the question?.....
013 No.
Ex OK, f ine.
|(i) 013 [Reads silently] - (b)(i) - expected ratio - urn - [Ex queries
long pause and encourages to think aloud] - well I m thinking
(b) - number of atoms that make up the molecule - ? [unclear] that
- A78 -
got anything to do with it - erm - can't remember anything to do with
that, so I'll go back to that.
Ex OK - fine.....
l(b)(ii) 013 [Reads aloud] well there's bound to be some inefficiency in the
apparatus - erm - [Ex again asks 013 to try to think out loud] -
I was thinking - one of them's - if there's not going to be a ratio
of 2 : 1 - one of them's not - either gonna not be produced, or it's
going to change into something else - erm
Ex Now - are you trying out possible ideas and seeing if they make
sense [a leading question!] — or what?••••••
013 - I'm stuck -
Ex - but you're thinking of something - you're not just there with
a blank mind -
013 I'm thinking of something - yes -.......water - H20 - erm
combined in - a ratio of 1 : 2 expected [this applies to part (i) of
course]- no - I'll go on again.
013 [Reads aloud] - there'll be more gas evolved - erm - [Ex asks
whence this quick, confident answer] - well - the more - gas combined
in subst' - the more - atoms combined to - be released - in the form
of gas - but I'm worrying about the current being kept constant
they're warning you about something - er - more would be evolved,
but it wouldn't be evolved any faster - I should guess so I
put more would be evolved [does so without reference to his idea that
it would be no faster].
1 (c)(ii) 013 [Reads aloud] - erm - well substances tend to break down quic
if they're heated - need less energy - so I should assume that gas'll
be produced faster - [writes].
- A79
1(d) 013 [Reads aloud] - well now you've got - wire - you've got a metal
- and it's - in the solution you've got ions - that pass from one
electrode to the other - er - taking charge with them between the
two electrodes and the metal you've got er - nothing's moving
vibrating slightly but not moving - how to condense that into two
lines - er - [Ex suggests he can run to 3 or 4 lines if necessary]
- I'm just trying to compose the answer - [speaks as he writes]. "In
dilute sulphuric acid - the electricity is conducted by moving ions
in the solution - but - in the copper wire" - ? [unclear] think it
is wrong - erm - [mutters to self - resumes writing] - "electricity
is passed from electron to electron without the electrons moving the
length of the wire •
Ex Right - now where did those ideas come from?.....
013 it's mainly out of Physics - you’ve got the - .....the structure
of the atom - you've got electrons circulating the nucleus and er -
the charge is carried - the electrons carry the charge - not the pro -
the protons [Ex encourages but tries to direct attention to how 013
remembered/constructed his answer].
013 - We were given a question on something like this - and I remember
him going over it - and explaining it - but it was quite a while ago
and I think I - ..... [Ex encourages further].
2(a) 013 [Reads aloud] - erm - the valency's - ammonium's - er
- carbon - erm - either CO3 or C02 - I think CO3 - can't remember
the valencies - erm - I guess ammonium's 1
Ex How were you trying to get that?
013 I was trying to - add up the 4 hydrogens - I know hydrogen's
valency 1 and nitrogen's valency 4 - add the. up got a valency 0 so
- that doesn't seem to work so I guess itis 1 - erm - try the same
idea with carbonates - er - 6 - 3 2 's are 6 - minus - that doesn't
- A80 -
TIGHTLYBOUNDCOPY
work either - I guess that's 2 - 1 can't remember that written down
anywhere -I'll leave a question-mark by it and go back -
2(b)(i) 013 [Reads aloud - erm - now test water - I remember it - two - one s
anhydrous copper(II) sulphate and one's - cobalt - chloride I think
- cobalt chloride - cobalt chloride [writes] - now - goes pink - I
think it's white to start off with [writes "white - pink"] - er -
I'm not sure about that - might be a better idea if I put down what
I know but I'm not sure if that's a proper test for it - I'll risk
it and put it down - [mutter] - ..... [writing] "anhydrous copper(II)
sulphate - white - plus water - goes to hydrated copper(II) sulphate
- blue" -
2(b)(ii) 013 [Reads aloud] - go back to the formula - NH2 - there's 2 of them
- now I think ammonia was tetrahedral - but that can’t - ? [unclear]
that - so - erm - 2 of them - er - come back [turns to next question
having written only]. [In discussion with Ex 013 explains he
was reflecting again on part (a) to see if the formula of urea seemed
to provide any help - but apparently not].
3(a) 013 [Reads aloud] - urn - ? [unclear] - sulphide urn [appears to have
passed straight on to (b)].
3(b) 013 [Reads aloud] - er - now there's some? [unclear] this one - acid
+ sulphide gives -
3(c) 013 [Reads aloud] -
Ex Well again can you try and think aloud
013 -top one (a) - manganese(IV) oxide - oxides - base - salts - acid
+ base - gives salt - plus water - that’s not a lot of use - urn no
- keep going down - see if I can find one I can do -
- A81 -
3(d) 013 [Reads aloud] - 's giving you a clue that one of them's an
oxidisng agent at least - erm ---
Ex Well - let me give you a clue - ..... I'm not saying anything about
the gas but manganese(VI) oxide is an oxidising agent - MnO^ - does
give you any clue how it might react with concentrated by hydrochloric
acid?
013 It's an oxidising agent?
Ex Mn02 is an oxidising agent - yes - it oxidises the hydrochloric
acid in fact.
013 Well hydrochloric acid's HC1 [writes this down] - em - if it's
oxidised manganese(IV) oxide’s itself reduced - erm - hydrochloric
acid oxidised - er - oxidised - take away hydrogen - so either
hydrogen or chlorine - could be given off - em - reasonable(?) gas
chlorine -
Ex You don't recognise this one as a lab' preparation? -it's
sometimes used as a lab' preparation but it may not be the one you
did -
013 No - I've seen manganese(IV) oxide before -
Ex Yes - it's often called manganese dioxide -
013 - Well I don't think it's the preparaton of chlorine - ? [unclear]
Ex What's the preparation of chlorine you know?
013 - don't -
E x ..... how aout the next one -it's also a lab' preparation - of
one of the gases in the syllabus.
013 - iron(II) sulphide - erm - never looked at the syllabus(?)
no - can't think of any gases at the moment - ? [unclear] this one
- er - iron(II) sulphide - Fe - S [writes] - iron - I'm crossing
- A82
iron out because iron doesn't make any gases with something else -
it's hydrogen in there [has written HC1] - there's sulphide in there
- hydrogen sulphide - now I know that gas - and I should guess that's
- the other one's chlorine - it's not the preparation of hydrogen I
don't think - so hydrogen sulphide - now comes the test - er -
hydrogen sulphide - erm - I think it's an acid gas but - wouldn't
bet on that — it's colourless — erm — no can't think of any test
offhand that - [Ex elicits that 013 remembers writing down that
H2S is colourless] - I used to get it mixed up with - I think nitrogen
dioxide - which is brown - erm - test for - well there's bound to
be a test for sulphide - no there's not - well there might be - er
[sighs] - ..... I'll put down an - test for acid - you could - use
an indicator - say litmus - colourless - as it's a colourless gas that
rules out quite a few - well same - so I'll say [writing] colourless
gas - erm - test using litmus as it is an acidic gas", [reads (c)
aloud again] -
Ex Well - again this a lab' preparation of a familiar gas.
013 - [Ex asks 013 to try to think aloud] - trying to think of the
lab' preparatons I know - gases - urn - I’ve come up against a brick
wall..... [Ex and 013 agree to move on to question A].
[a) 013 [Reads aloud] - erm - heat of neutralisation - the heat - ?
[unclear] neutralisât - ? [unclear] the heat at which - the heat
generated by two substances when they're added together - while
they're neutralising one another - put that in English - would be
quite difficult - er - [writes] "the heat produced - when the acid
plus the alkali are added" - well, they've given me - I’m not sure
if that’s supposed to be another line to write on - if It is I’ve
, t * 1 1 lust er — I'll leave that ~ 'ndone a short answer - em - well I H Ju
go back.
- A83 -
4(b)
4(c)
4(d)(1)
4(b)
013 [Reads aloud] - erm - I think it's (?) something to do with -
absorbs the heat - er -
013 [Reads aloud] - [Ex encourages to think aloud] - I seem to
remember doing this when I was away and I forgot to copy up the notes
- er - well it was - vaguely the same amount of both of them - and
- yes - the same amount of acid - and therefore same amount of
hydroxide - suppose you could say the acid's are the same
concentration - which - I dunno - well here I'Id have a guess - er
- "the same amount of acid" [speaking while he writes] "and alkali
were used and the concentration of the acids was the same .
013 [Reads aloud] - therefore if what I've said before's right the
same would happen - 'cause the same amount and it's 1M - erm - I hate
chemistry!
Ex Now you tell me! -
013 er - well I'll stick to my guns and say the same - temperature
rise would be the same [writes] - and if that's true the other one's
true [referring to part (ii)] - and (d)(ii) would be the same [writes]
- [Ex establishes that 013 did not recognise ethanoic or acetic acid
at all and refers him back to part (b) where no answer was written].
313 - Well you're making - producing heat and er exothermic
reactions we've done - if you hold the test tube it gets warm - so
the - heat is being transmitted by the glass - so I should guess the
plastic's used to stop this - something like that [appears to be
proposing a likely seeming hypothesis] - em - "because" [writing]
"containers made of other substances may" - er transmit - er - [sighs]
- conduct, that's the word I want [this word was provided by Ex!] -
- A84 -
"conduct heat-invalidating..... " will that confuse him if he doesn't
understand what I'm talking about? - ? [unclear] experiment..... [Ex
encourages]•
5 (a) 013 [Reads aloud] - I'm just looking at the table - [continues]
right the mass number is - I remember - the number of protons plus
the number of electrons - em - now isotopes - an isotope - is -
something that’s got - oh heck - definition of an isotope - em - well
I reckon it'Id be too simple if they'd given you two numbers the same
- they're 18 - so must be same number of protons but different number
of - different mass number - so I'll take - all the top numbers -
the number of electrons - from the mass number - 6 , 10, 14, 16, 18
er 2 2 ..... . - well - if what I just thought was right - someone
made a mess-up of the question - so it must be the number of electrons
that's the same - so - or is it the atomic mass number? - no it must
be the number of electrons - so I ’ll say M and - it looks like Q -
5(b) 013 [Reads aloud] - now - er - the first two got 2 then 8 and 8 and
8 - so equals 2 and 1 0 - 18 - 26 - right - you got - 1 2 - same group
- periodic table - are groups the ones that go down - so - there's
two atomic masses the same there - erm - going back to the last
question - think I'd better change that - to Q and X -
Ex Now - why have you done that?
013 Well, I've got two numbers the same - and I m trying to remembe
- carbon - that's - ? [unclear] getting mixed up with isotopes and
allotropes - no isotope's what carbon's got - and - every element
has got one atomic mass number - which can't be right - no - it's
got one atomic number - getting really confused -..... mass number
- well - see if I can settle myself down and come back to that in
a second -
- A85 -
t
i
5(c) 013 [Reads aloud] - now halogens are in the - 7th group - 7th group,
therefore it's going to be 7 + 2 - 11 - no there's nothing 11 - plus
another 8 - 1 9 there's one there 19 - there's one up there 19 as
well - no - must be mass number - another 8 's 27 - no another 8
is 3 5 and it's which element so it's singular anyway - M Y should
guess G [!] •
5(d) 013 [Reads aloud] - X reacts with L - now X has got mass number of
40 - erm - it’s - now - erm - well to find that you're going to have
to find out which group they're in - therefore what valency is - so
to find out what group they're in - take X - and - start with 2
take 2 away from that's 38 and divide by 8 - em 32 - 4 times - which
leaves 6 - so I guess that's in group 6 - so its valency's 2 - X
valency 2 - and L - 's 32 - take off the two for the top row - 's
30 - divide by 8 - er - 24's 3 - that's 6 left over - so it's in group
6 again so it's - another one in group 2 - now what's 2 gases
| oxygen's in group 6 - er - ? [unclear] - well 32 + 8 is 40 so they're
in the same group - so - XL - now -
5(b) 013 [Reads aloud again] - er - same group going down - well I’ve got
X and L - er - so if you add 8 to L you get X - the mass number -
and you've got 12 here - 12 plus 8's - plus 1 6 's - 28 - so it's going
to - think of some logical way - which two elements are in the same
group - ohm - it’s not as if I’ve got a table - so - you have
[draws/writes] - first lots there’s a 2 - one ? [unclear] doesn't
matter - so you've got 3, 4, 5, 6, 7, 8, 9, - 10, 11, 12, [is writing
these under group numbers 1 - 8 ] - ? [unclear] numbers 1 2 to
13, 14, 15, 16, 17, [Ex stops at this point and discusses the item
briefly - number 6 is skipped owing to lack of time].
- A86
7(a) 013 [Reads silently] - atomic level - define oxidation in terms of
changes at the atomic level - skip that bit - don't know what it's
talking about -
7(b)(i) 013 [Reads aloud] - now - I've been given something to learn
oxidation is - gaining, of oxygen, loss of hydrogen and the loss of
electrons - so - which one's being oxidised - Fe is --- hydrogen is
losing an electron - 'cause it becomes + so it's lost one electron
- erm - hydrogen is being oxidised - so's Fe - but hydrogen's
element - oh - I'll underline Fe.
Ex Why did you pick on Fe in the end? - sorry I didn't get the last
bit.
013 em - well hydrogen - don't know if hydrogen can be oxidised but
- something - in each equation something has to be oxidised and
something has to be reduced - urn -
Ex All I was asking was why did you suddenly decide to underline the
Fe?
013 - pot luck! - ..... [at some stage has written in margin +0, -H,
-e] -
(ii) right go back to this one - Cu - you've got copper turning into the
ion - the element turning into the ion and you're - losing 2 electrons
so - er - let's pick on bromine instead - bromine's negative - so
it’s gained electrons - that'Id be reduced so I'Id say - copper's
been oxidised.
7(c)(1) 013 [Reads aloud] - don't think we’ve done this yet
Ex Well I think - yes I’m sure you have..... [suggests turning
sulphur(IV) and (VI) oxides into - more familiar names]
013 Oh - sulphur - valency 2, 4 or 6 - there it s 4 - and you ve got
2 oxygen combined - so it's sulphur dioxide - so the other one is
- A87
I sulphur trioxlde..... [sighs] - er now the contact process is
something to do with acid - it could be to do with one of these two
as well - erm - well contacts a nice word so I'll put that down [Ex
queries but no additional information forthcoming].
7(c)(ii) 013 [Reads aloud] - that's the Haber process - [writes]
Ex Let's go back before you go on to part (a) - when you were doing
part (b) - trying to sort out which one was oxidised - you had some
ideas - about what an oxidising agent was - would those help you to
answer 7(a)?
013 Don't understand what it means by in terms of changes at the
atomic level - er - hold on - Miss Disney was talking about something
about sulphur - going from - different valencies - that could be it
- erm - [mutter] - no - .....
8 (a) 013 [Reads aloud] - no - this is learning um - er
Ex ..... any special way you’re trying to remember it?
013 Well, it's got a complicated name - or a funny name and, we
did it when we did the hardness of water - erm - ..... trying to
remember a page in my notebook - er - it was just after we
an experiment with soap - and - detergent - but I can't remember it.
8 (b) O U [Reads aloud] - er - going to have difficulties here cause I
don't know what it's called - well - the soap combines with - the
calcium and magnesium ions in the hard water - to form - a substance
- scum - well I can't think of anything else to write so I'll put
that down - [writes] - erm - the compound that soap is made of
combines with the calcium and magnesium ions to produce scum - now
- explain why soap will not lather well - well - most - of it [that]
would lather's - been reacting - 'cause it can't do both things
once — um — fed up with that one! —- A 8 8 -
sulphur trioxide..... [sighs] - er now the contact process is
something to do with acid - it could be to do with one of these two
as well - erm - well contacts a nice word so I'll put that down [Ex
queries but no additional information forthcoming].
c)(ii) 013 [Reads aloud] - that's the Haber process - [writes]
Ex Let's go back before you go on to part (a) - when you were doing
part (b) - trying to sort out which one was oxidised - you had some
ideas - about what an oxidising agent was - would those help you to
answer 7(a)?
013 Don't understand what it means by in terms of changes at the
atomic level - er - hold on - Miss Disney was talking about something
about sulphur - going from - different valencies - that could be it
- erm - [mutter] - no - .....
8 (a) 013 [Reads aloud] - no - this is learning - um - er -
E x ..... any special way you're trying to remember it?
013 Well, it's got a complicated name - or a funny name - and, we
did it when we did the hardness of water - erm - ..... trying to
remember a page in my notebook - er - it was just after we'd done
an experiment with soap - and - detergent - but I can’t remember it.
8 (b) 013 [Reads aloud] - er - going to have difficulties here cause I
don't know what it's called - well - the soap combines with - the
calcium and magnesium ions in the hard water - to form - a substance
- scum - well I can't think of anything else to write so I'll put
that down - [writes] - erm - the compound that soap is made of
combines with the calcium and magnesium ions to produce scum - now
- explain why soap will not lather well - well - most - of it [that]
would lather's - been reacting - 'cause it can't do both things at
once - um — fed up with that one! —- A88 -
8 (c) 013 [Reads aloud] - erm - an acidic salt - erm -
Ex Now again - what's going on inside?
013 I was thinking of the preparation of sodium hydrogencarbonate
- erm - I think sodium hydrogencarbonate1s an acidic salt - and I
think sodium carbonate's an alkali - if you add both to water - then
- test it for acid or alkali - erm - ? [unclear]question - [writes]
"add water then test using an indicator- for acid or alkali - sodium
hydrogencarbonate would be acidic".
TAPE ENDS
- A89
■
PUPIL 014 - TRANSCRIBED PROTOCOL (TEST 03)
1(a) 014 [Reads aloud] - the first thing that comes to mind is ox' -
sulphuric acid - hydrogen and oxygen - 'cause their about the only
things in it - that are gas - well sulphur dioxide as well - erm -
stuck between them - I think one's definitely hydrogen- er - [mutter]
- so it's between them 3 - ..... erm - hydrogen I think [softly]
..... I think it's hydrogen -
Ex This is for the anode is it?.....
014 - hydrogen at the anode - yeah [writes] - [reads] "state the name
of the gas formed at the cathode" - er - I'm not really clear about
this actually, it's sort of all in my head - I'm thinking about that
glass with the two electrodes in it and all that - er - - oh yes -
because I definitely know for water it's hydrogen and oxygen - ?
[unclear] - [whether]? it's still sulphur dioxide - [whether]? that's
in it - er - um - I think it's oxygen - I'm not sure I might have
them the other way round - [writes] - right next one.
1(b) 014 [Reads silently] - ah - I think's because it's soluble - the
volume of one gas - something to do with soluble - I'm not sure
em - [mutters] - 1 : 2 ratio is expected - er - oh - it's l^SO^- er
stuck on that one - [Ex enquires which gas he thinks there is more
of] — I think hydrogen will be the 2 — and oxygen the 1
Ex What makes you think that?
014 Valencies for some reason - er - 'cause oxygen's 2 hydrogen s
1 - er - H_S0.- I'm thinking 'cause oxygen’s 2 hydrogen's 1 - er - 2 4
H2 S04 - I'm thinking 'cause it's H2 - then there's the S04 group
which has got a valency of 2 - er - - 1 : 2 ratio - something to do
with - [mutters softly] - actually it's dilute so it will have water
in as well - [unclear mutter]..... be ions - SO^ - I 1 1 have to do
something about time(?) - ? [unclear] diagrams, whatever - er S0 4 -
- A90 -
- 2H - positive - half a tick - I think that's right [writes SO^ ,
2 H^] -the other way round - no, that's right - erm - now I get stuck
with the ions - and things like that - SO^- it'll be - 3 (?) of
water it'll be - it’s really - positive - OH - negative - em - yeah
- I'm definitely sure it's - [grunt] - I'm a bit confused now - er
it's definitely hydrogen - 1 : 2 - I think it's something to do with
the water there - because you're getting ions from both the water
and the sulphuric acid - um - I feel I'm just getting on to it - [Ex
encourages to press on] -
014 S04 two neg - I'm a bit stuck with that - I'm not sure if I can
get some oxygen out - out of that - I can't see where it's come from
- it's either come from the OH negative there - but I think if
that'll be ox' - oh it's er - the bottom of (here?) - 'cause I
remember the equation - it'll be 4 - 4 OH negatives - erm - so it'll
be OH - you have to add electrons to that - it'll be - OH - I think
its 0 2 - plus H 2 0 - can't remember - er - yeah it's just that bit
there - I can remember the bottom of the equation - but I can t
remember the (writing?) - you know 'cause we - do writing sort of
to explain how each one's at the cathode - and the - anode -
Ex Do you remember how you decide which one's at the anode and which
ones at the.....
014 Yeah -it's the charge there - I'm sure it is - anode's - yeah
- it's the anode's positive - I always consider hydrogen and oxygen
as boarder cases between - the erm - non-metals and the metals - they
always seem to be inbetween when you sort of - because of water
its ? [unclear] often inbetween - 'n I always get them mixed up - I'll
go to the next one and leave that one. [Ex congratulates on the
"thinking aloud" and encourages].
l(b)(il) 014 [Reads aloud] - that's because it's been dissolved in the water
- I'm definitely sure of that - erm - some hydrogen - ? [unclear]
- A91
H 0 _ hydrogen's dissolved in the water - I think it's soluble -
solubility of gases now - er - go through the lot - er - hydrogen
oxygen [under his breath] ~ well it's “ a 1;2 ratio — if there s
twice as much hydrogen - I think it's the hydrogen 'cause hydrogen's
(dissolved?) in water - ..... (I'm not so clear or I haven't a clue?)
- it's a while since we did electrolysis and I'm a bit - erm - 'cause
when I tend to revise electrolysis I tend to do the - sodium chloride
- the electrolysis - the - industrial er - and the - the hydroxide
one as well - where you get sodium hydroxide - well the Down's Cell
and the - the other cell..... suggest a reason why it is not obtained
in practice - hydrogen's dissolved - I'm sure it is [writes].....
l(c)(i) 014 [Reads aloud] erm - well I always though that - sulphuric acid,
when it's not in, dilute solution, doesn't electrolyse actually
because it’s got no ions in it - it's just a covalent - liquid - I
think increasing the temperature of the sulphuric acid would increase
the rate - [under his breath] increase the rate - of hydrogen and
oxygen evolved -
Ex Now - why do you think that?
014 Well - because - when you heat something it usually becomes more
reactive - when yer - ? [unclear] - experiements about - the - the
size of the pieces - ..... see what I mean......gives it more
activation energy and things like that - [Ex asks 014 to try to do
his thinking aloud and not just the answer]..... [rereads part c(i)
aloud] - I think that will, actually, slow it down - because it's
becoming more into a covalent molecule - I'm not sure - I'm not sure
at all - - becomes a covalent molecule - I'm not very sure about that
- (don't?) remember - starting the 4th year - we did all this
[writes] - liquid - better word than molecule - um - I'm not very
- A92 -
sure about that at all - [has already written answers to parts (i)
and (ii) at some earlier time].....
1(d) 014 [Reads aloud] - erm - oh dear - I've forgotten about copper wires
- er - I don't think we did - ? [unclear] - I can't remember - I
always remember copper - electrolysis - the copper - the bits of
copper going from one to the other or coming out of solution of
copper(II) sulphate - but I can't remember sulphuric acid - I imagine
it's the same thing actually - somewhere around the same thing - erm
- acid - urn - stuck on that completely - [Ex suggests going on to
the next item; 014 is keen to leave it open and return to it later
but agrees to try the next question].....
2(a) 014 [Reads aloud] - oh - it's NH3 or NH4 I know NH - I think NH3's
ammonia so it's NH 4 - [writes] - carbonate - C03 I think it's got a
valency of 2 [mutter] - yeah that's right - definitely - [has written
nh4c o3]
2(b)(i) 014 [Reads aloud] - oh dear - I'm lost here - and haven't done
anything about that - (think I'd better change my mind and go back?)
- erm - [reads part (i) aloud] - erm - some - we can use universal
indicator I think - for water - it goes - somewhere inbetween - is
it blue or green - I don't know - universal indicator going from -
purple at one end - that's the alkali - 14 - pH 14 down to - PH1 of
red I think - bright red - but there's something else - there's a
piece of paper - pink and blue comes into me mind er - oh - cobalt
- I think it's cobalt - cobalt chloride - I think it goes from blue
to pink when you dip it in water - yeah that is right
Ex Is that from your chemistry or your biology?
- A93
,Kr; ,
014 actually that's from my biology -..... "from light blue” [writing]
- yeah - we've done that - can't remember when it is - actually it
was recently - something about - photosynthesis - pink - I can
remember doing cobalt chloride paper in the first year when we were
doing something about - copper - copper(II) sulphate - or something
like that but - I haven't got my books for the first year -
2(b)(ii) 014 [Reads aloud] - drawing - NH2 - 2 - CO - structural - that like
tetrahedrons come in my mind there — things like that — structural
formula - oh - it's got a diagram somewhere - NH2 - CO - I'm thinking
of those circles with the dots in that'll show the different covalent
bonds at the moment - I'm not sure - NH2 - so there's two of them -
and one of the CO's - so I'll put the CO there - in a circle - so
you have a circle - show that's a molecule - now - you've got to have
eight - er - I can remember doing water and things like that - and -
urn - we've just done the - hydrocarbons - the gases ethane and things
like that - and I'm thinking of those diagrams but I'm getting a bit
mixed up - because we do diagrams of the angles and their different
- parts of the molecule - 109° - I remember that - 108, 107 - but as
far as it goes for that I can't remember anything else
Ex You're not quite sure what we mean by a structural formula?
014 No - I know - I've heard that before but it seems to have (lost?)
my mind here - [Ex explains that what is wanted is "just the lines
-and - as you say - those angles like - you don't need to draw all
the electrons"].
014 Right - I'm going to use pen - erm - so it’s NH2 - so it's CO
in the middle - and it's either like that - ? [unclear] - NH - two
lots - that'll be NH2 [drawing] - and it's a linear sort of molecule
- yeah I think that's it - now there must be - let's think of the
bonds - oh it doesn't give me - erm - thinking about the number of
A94 -
:
lines there - CO has only got a valency of one - no - I can't work
it out just from the valency I don't think - em - yeah I'm probably
satisfied with that - as it is - but I'm not sure
3(a) 014 [Reads aloud] - chlorine - definitely - ..... that's straight off
- I knew about that defnitely - because that stuck in my mind from
last year when we - ..... definitely revising from my note book for
the last exam' - the mock 0-level - ..... chemical test - white smoke
- oh dear - just remembered a white smoke for chlorine - no - hydrogen
chloride that is - chemical test - well it's an acidic gas - I know
that - I think if yer - moist - some moist paper - pink - ah that’s
it moist litmus - moist blue litmus - yes I think it turns - yea
that's right moist blue litmus because - that would be like an alkali
if it's blue - and if it turns red that means it's an acid - to me
it does anyway - moist blue litmus - yeah [writing] - turns red -
can remember doing that and dipping it into a gas jar, and it stuck
- er turns red again on mixing with chlorine - yea - all I can
remember about that is the gas jars and - and things like that and
I'm writing it down - .....
3(b) 014 [Reads aloud] erm - hydrogen sulphide - now I remember that
because of the smell - hydrogen sulphide [writes] - yes - ? [unclear]
been revising as well - because I remember, for the third year exam
I revised a hell of a lot for that - name of gas - oh chemical test
- oh dear - erm - urn - there’s a vari’ - there's many chemical tests
for gases but I - just can’t seem to put my finger on hydrogen
v, „)„ai i-pst - oh - stuck on that - no I think sulphide - erm - urn - chemical test on, v i, At- - T'm not really sure about theI'll leave that and come back to it
chemical test.
- A95 -
3(c) 014 [Reads aloud] - I think that's ammonia - yes ammonia - we haven't
done that actually -
Ex Why do you think that's ammonia then?
014 Saw it in a book - me text book - I usually have a flick through
the book (when I've done my ?) homework - sort of turn over the page
and have a look at something else..... - chemical test - that s
hydrogen chloride gas - or you can dip a piece of filter paper in
some hydrochloric acid - concentrated I think - and it gives off a
vapour and if you mix it with the ammonia it gives a white smoke of
ammonium chloride - that’s how I remember the white smoke from the
previous question -
Ex So you're remembering this as a test for hydrogen chloride are
you?.....
014 Yeah - and using it the other way round - [writes and speaks]
"filter paper soaked in hydrochloric acid" - yeah - white smoke seems
to stick with me most -
Ex Yes - that's from seeing it presumably?
014 Yeah - definitely - [continues writing] "white smoke of ammonium
chloride" - done quite a lot of em actually - so I remember that -
3(d) 014 [Reads aloud] - erm - chlorine - we did an experiment with a
flower - put a flower into a gas jar and put some chlorine in - I
think - yeah - and the pigment went out of the flower's petals - went
from pink to white - chlorine I'm sure it's chlorine -
Ex Now what's that got to do with an oxidsing agent - this flower
going from pink to white?
014 Well - I'm not sure if it was chlorine or if it was sulphur
dioxide but it's the same principle I'm sure it was - um well it
oxidises it - like when you have - newspaper - you use sulphur dioxide
I think for newspaper - it turns it white but then it gradually goes
- A96 -
yellow over the years - gets oxidised - oxidised - yeah - I think
I'm sure about that - I wouldn't know about ammonium - ammonia, 'cause
we haven't done it yet - [Ex Encourages and instructs to omit item 4
as previously agreed with chemistry teacher].....
014 [Reads first sentence] - don't like these - [starts to read second
sentence after little or no attention to the table] - Using the
letter at the" - I prefer actually the experiment in front of me -
'cause you never actually see a molecule - in your own mind - ?
[unclear] - 'cause they're so small - you don't really know how to
represent them in your own mind - except for all the diagrams you
use with - bits of polystene - polystyrene - ? [unclear] nails stuck
in - [finishes reading the sentence under the table] - letter at
the top of the column to represent the element" - urn - isotope - oh
- oh dear - I can remember doing that with chlorine I think - m
finding it hard to take in this question actually - it's a bit mixed
up - think I'll read it again - [rereads aloud - but not the table]
- oh right - I think - [rereads (a) aloud] - well - isotopes - let
me see - I think it's M and Q because they've both got the same number
of electrons but different number - mass number - which means -
neutrons - which have got no - electrical charge - there's 4 more
- I think it's - an isotope - oh dear - ? [unclear] about definition
- erm - something to do with the relative weight - to the number of
electrons and - protons - protons are positive, electrons are negative
- if - the number of electrons in the outer shells must equal the
number of protons in the nucleus - yes -
Ex You're sort of checking up on this are you?
014 Yes - I’m checking up - I’m trying to think of all the definitions
and - twenty pages of it - oh - dear - M and Q I think - if there's
no more number of electrons the same - 'cause it's impossible to be
- A97 -
an isotope if they've got different number of electrons 'cause they'll
have different - structure on the outside - different reactivity
em _ yeah - M and Q - definitely on that.
5(b) 014 [Reads aloud] - oh dear - periodic table - I'm a bit stuck on
this - x don't know much about the periodic table at all except
there's a board in the other room that's got the periodic table on
- and it's at the back of my text book - I don't look at it actually
- it confuses me - we haven't done it - we haven't got a - table (or
anything like that ?) yet - that - the periodic table - brings to
me mind calculations for some reason - use it for calculations or
something - for the - volumes of gases - (wouldn't ?) be gas I think
but something (there ? like that ?) - which two elements are in the
same group of the periodic table - I think I'll have to find the same
numbers again - urn - I think it’s them two - Q and X - for some
reason - 'cause they've got the same number - similar numbers seem
to mean smething to me - em - no - I'm a bit stuck on that
Ex OK - well if you haven't done periodic table.....
014 I'll put Q and X anyway so -
5(c) 014 [Reads aloud] - er - halogen - chlorine, iodine bromine, fluorine
- oh dear - they're sort of all mixed up in one big table - next to -
the end of my book - er - mind's just floating through them all at
the moment - chlorine - valency - er - trying to think of the electron
formula - it its valency 1 - er - 2, 8, 9 no - yes - - 2, 8, 9 ’cause
that means it'll be - negative and if you take - yes 2, 8, 9' s it's
stable and if you take one electron off it makes it stable - no 2,
8, 9 isn't stable - 2, 8, 8 is - that's number of electrons if you
see what I mean -
Ex Yes -
- A98 -
014 er - just a minute - which element is a halogen - 2, 8, 9 - that's
1 9 - oh - um - a bit stuck on this - actually it doesn't have to be
that I don't think - fluorine - they're all valency 1 I think - except
- for bromine - I'm not sure - er - no iodine's valency 2 - is it?
- chlorine, fluorine - definitely valency 1 - iodine - iodines
definitely - yes - because hydrobromic acid in a table at the back
of my book - is HI - yes definitely valency 1 - erm - I have to think
of other formulas - when I'm trying to find the valency if you see
what I mean -
Ex Yes -
014 er - in order to find the valency of hydrogen - you know - I do
know it but if I didn’t - I'Id say - sulphuric acid - H2S04 - S04's
valency two therefore —
Ex Uh - hu -
014 ? [unclear] - which element is a halogen - erm - um - it’s none
of these - none of the even numbered - 9 - u m - G - 2 , 7 - a h - 2 ,
7 - no that won't be, because to give that stable - it'll have to
be 2, 8 - ah no - wait a minute - I think I've been going wrong here
- I think it is G - 'cause if - if you take - no - if you take an
electron off it becomes - postive, put an electron on it becomes
negative - and G - if it's got the number of electrons is 7 - I mean
9 - the first shell’Id be 2, second 'Id be 7 - then you have to add
one on to make it stable - I think it’s 9 - yeah - I'm a bit stuck
with that actual - yeah G - I found it 'cause I was just looking
at the number of electrons to make it a stable shell -
Ex Yes -
014 Right -
5(d) 014 [Reads aloud] - X - 19, 40 L - I'll have to find the valency of
L - 2, 8, 6 - s o it's going to be L valency 2 - 1 think I 11
- A99 -
these down here - I've worked that out from 16 electrons - er - that
means the shell'Id be 2, 8, 6 - so If you want to make it stable -
to 2, 8, 8 - you'll have to have one - two electrons - no - negative
- SO it'll be - L 2 - I'll put 2 the valency of L is 2 erm - plus
[has written 16, 2, 8, 6 + 2 electron L2 +] - now X - er 2 - if it's
19 electrons it'll be 1, 2, 8, 8, 1 which'11 make it - you knock one
off it'll be - X - 'll be neg' - '11 be positive - positive with a
valency of 1 [has written 19, 2, 8, 8, 1 X ] - 'n that'll be - 2
negative so'll be - IX, - yeah - IX, - I think that's right - urn -
yeah I'm po' - fairly - fairly sure on that - you see the fun' - the
funny letters put me off a bit - give sort of N or something different
you know -
Ex Yes -014 - ? [unclear] - like doing the question actually - er - gives
me the impression it's not trying to - test me on what I know about
different - it's more the theories behind it more than anything else
- I think that's - more than actual - things that are in chemistry
it's [trying to test the ?] theory which confuses me a bit - [Ex
encourages and suggests he moves on!].
014 [Reads aloud] - "reddish brown precpitate was formed" - I'm
confused on this one already it’s so long [laughing] [continues
reading and completes] - I'm reading through that again - if you don't
mind I'm just going to read this on my own - I think the excess iron
filings is used in this - urn - I think it's because then you'Id use
up all the copper(II) sulphate or something - you'Id use - 'cause when
you add an excess - the excess - means to me that you'Id use up all of
the other solution - you add an excess of magnesium to - hydrogen -
hydrogen - hydrochloric acid so you use up all the hydrochloric acid
things like that - that seems to bring something to mind test
- A100 -
6(b)
little bit of -'n a massive excess of metal and there's a little bit
of hydrochloric acid in the bottom and 've got your thumb over the
top - erm - an excess - and it's underlined that makes it even more
certain - reddish brown precipitate - that seems to be - crystals
prepared [under his breath] - iron(II) sulphate - yeah - it must be
- to use up - iron - because that replaces all the copper - I think
[writes] an excess used because - it would use up - replace - all
copper - from the copper(II) sulphate
014 [Reads aloud] - crystalising the solution - erm - I think the
reddish brown - oh precpitate - it must be - iron(II) sulphate -
can't be anything else because you can't - you can’t call copper a
precipitate really - on its own - I've called it that - I've never
known anybody - I'm not sure - that word precipitate seems to bother
me a bit - because iron(II) sulphate I'm not sure what colour that
is - you know iron and rust and things like that - (you do get that?)
brown colour but - I'm not sure - hm - the more I think about this
the more doors are opening - the more different things it can be so
_ ..... Well, I'm just thinking about copper, iron - er - the different
things - I mean - think of what - iron and chlorine now - the yellow
and the green coming right down to the different valencies - iron(II)
sulphate FeS047H20 - I’m sure it's iron(II) sulphate which is left
- the filtrate - was evaporated taking all necessary precautions -
taking all necessary precautions [surprised] - seems to imply
toxic or something - until a saturated solution was formed - the size
of the question at the top seems to bother me -
Ex Yes - there's a lot there isn't there.
014 Yes - urn - the way the sentences are broke up too - they’re all
small sentences - er - [reads (b) aloud again] - well it must be the
copper - urn - no - no - er - oh dear - yeah -
- A101
Ex I get the impression that you're trying to juggle too many things
in your mind at the same time - is that? -
014 - I'm trying to follow a direct line of thought - instead of just
sort of spreading out - a pyramid and going to more and more -
Ex Yes -014 - so it's - equation..... that 7H2<) seems to be a bit - [mutters]
- CuS04 + Fe equals FeS04 + [writes Cu silently] - I can't see how
it can make - I can't see how - copper can be on its own - that seems
to be right though to me - though the Fe and the Cu on their own look
a bit strange - ? [unclear] - em - [rereads (b) aloud again] ?
[unclear] - urn - I'm in doubt - I think I'll - no I ’m not going to
leave it out because I think I’m going to get the answer soon so -
[mutters] - I think it's the copper - if you're going to make crystals
of iron(II) sulphate you're going to have to filter off the copper
- yeah -
Ex OK -014 "Which of the substan..... "[starting to read (c)] oh.. and
the excess of - excess of iron filings [adds this to answer] - right.
) 014 [Reads aloud] - hm - oxidising agent - can't see where that's
come into it - can't see the oxidising agent in there - em - filtrate
was evaporated - [sighs] [Ex suggests that owing to time constraints
they skip through a few - 014 interrupts and reads part (d) but
says]....afraid I'm lost on that completely [and at Ex's suggestion
passes on to part (e)].
e) 014 [Reads aloud] - ..... - - - this is something to do with
calculations now - that puts me off I m no*- su
Ex You don't like calculations?
!
OlA No - well - we haven't done them yet - oh I don't mind maths -
maths is all right - I like maths but - [this is in line with what
teacher has told Ex so it is agreed to move on to the next question],
7(a) 014 [Reads aloud] - atomic - big words - um - well I can think of
two already - the loss of oxygen - gain of oxygen of a substance -
or the loss of hydrogen - or the loss of electrons is it a loss of
electrons - oh urm - I know it's - [and I ?] think that's what you
mean - you're implying that - something about - ions - electrons -
er oh leo - that comes into my mind - and ger - loss of electrons is
oxidation gain of electrons is reduction - a loss of electrons they're
two little - leo and ger -
Ex Yes - I've come across them -you've talked quite a lot about your
revision at various times now — when you remember something because
you remember revising it - are you - sort of seeing it on the page
there so to speak or what? - .....
014 No - more.....
Ex ..... or it's more abstract in your mind?
014 - more or less it's a mixture of experiments I've seen - and -
things out of the textbook - I seem to remember a lot out of the
textbook actually - more than I usually do - when I'm in exams - you
know - when you're -
Ex When the pressure's on sort of thing?
014 Yes — I seem to remember more — you know I just can't believe
- oh I remember that! — you know I remember that — I just don't know
how 1 remember them actually — yes — a loss of electrons is oxidation
- I remember [we were doing ?] a bit about oxidation — it's been
hovering around - chemistry - since about the first year until -
different teachers I've had talk about oxidation — it was only
actually explained in the 4th year - so you know - that should be
quite well ? [unclear].
- A103 -
■ h pm
I 7(b)(i) 014 [Reads aloud] - now - I'll explain that em [has underlined H ] -
iron three positive which means it's got - three electrons missing
in a way if you put it like that - it's changed to iron two plus -
which means it's actually gained an electron to take away one positive
charge - and the hydrogen's gone to H which means it's had an
electron taken off it - so loss of electrons is oxidation therefore
it must be the hydrogen - that's how I work it out - and er - I'm
going er - I think that's - I've never seen that reaction so I'm not
remembering or anything like that - that's just straightforward
learning - the laws - .....
014 [Reads second equation] - er - oxidaton — 2Cu plus - er - they re
not ionic there - 's funny - thought they were both sides - er - Br2 -
that seems as though - this seems as though - erm - you've missed
out - this is only part of an equation where you should have 2Cu
something else - goes from being covalent to ionic in a - a reaction
- er - er what can I say - I reckon the copper's been oxidised because
it's got the two positives and - I'm not sure whether it has there
'cause it seems stable there - that definitely hasn't - 'cause that s
a gain of electrons [referring to the Br?] so the copper - because
the bromine - is negative - that means it's gained electrons - that s
not oxidation - [note however that in both equations 014 has under
lined substanstance that has been rather than that is being oxidised].
014 [Reads aloud] - erm -
Ex you might have different names for these — if you want the other
names I can give them to you -
014 erm - catalytic oxidation of sulphur - to sulphur dioxide - erm
- I'm afraid I don't know that all -
- A104 -
7(b)(1)
*
I 7(b)(ii)
>
>
7 ( c ) ( 1 )
014 [Reads aloud] - now - I'll explain that em [has underlined H ] -
iron three positive which means it's got - three electrons missing
in a way if you put it like that - it's changed to iron two plus -
which means it's actually gained an electron to take away one positive
charge - and the hydrogen's gone to H which means it's had an
electron taken off it - so loss of electrons is oxidation therefore
it must be the hydrogen - that's how I work it out - and er - I'm
going er - I think that's - I've never seen that reaction so I'm not
remembering or anything like that - that's just straightforward
learning - the laws - .....
014 [Reads second equation] - er - oxidaton - 2Cu plus - er - they re
not ionic there - 's funny - thought they were both sides - er - Br2 -
that seems as though - this seems as though - erm - you've missed
out - this is only part of an equation where you should have 2Cu
something else - goes from being covalent to ionic in a - a reaction
- er - er what can I say - I reckon the copper's been oxidised because
it's got the two positives and - I'm not sure whether it has there
'cause it seems stable there - that definitely hasn't - 'cause that's
a gain of electrons [referring to the Br7] so the copper - because
the bromine - is negative - that means it's gained electrons - that's
not oxidation - [note however that in both equations 014 has under
lined substanstance that has been rather than that is being oxidised].
014 [Reads aloud] - erm -
Ex you might have different names for these - if you want the other
names I can give them to you -
014 erm - catalytic oxidation of sulphur - to sulphur dioxide - erm
- I'm afraid I don't know that all -
- A104 -
Ex Well sulphur(IV) oxide is sulphur dioxide and sulphur(VI) oxide
is sulphur trioxide.....
014 Yes - now - got to think of the name of it - name the industrial
process used in the following era - ..... so - this is an actual
industrial process that makes something - so I've got to say what it
makes - is that -
Ex No - we're asking for the name of the process - which involves
oxidising sulphur dioxide to sulphur trioxide
014 I can remember doing printing or something - you use it to make
white paper or somethng - is it pulp? - I'm sure it is - something
to do with paper - I think I'll put paper 'cause I’m not very sure
about that - I remember doing sulphur trioxide in a conical flask
and - platinised asbestos - with two gases coming out - oxygen and
sulphur dioxide 'n they mix at high temperature - 'n you get a white
smoke and - the conical flask is enveloped in ice and - salt stuff
- various things - I think that's right - 'cause - that's in my book
- it's in that area where we've done something about paper - I’m not
sure - but - in me book - what I can remember it tells me that that's
right - but I suppose in my own mind I'm sort of thinking it might
not be -
c)(ii) 014 [Reads aloud] - haven't done that yet - er - no - I'll leave that
- [Ex agrees they will go on]•
8(a) 014 [Reads aloud] - something to do with sodium oh no er ST
sodium stearate - I think that's Na.St. - something like that [writes
it] - I think I’ll put - I think I’ll put the name - yeah [adds it]
- that's all I can remember from that.
- A105 -
8(b) 014 [Reads aloud] erm - hardness of water - limestone seems to come
into mind there - some stone - er - water - rainfall - er calcium
- [seems to be?] a mixture of sodium and calcium - explain why soap
will not lather well with hard water - hard water means - I know it's
the whole idea - hard water means water that'll not lather well
so that doesn't get me anywhere - oh dear - hard water - because it’s
something to do with the reaction - urn - oh - sodium hydrogen
carbonate [obviously scanning the next part of the item] - that s
[unclear] -Ex You were looking down at the later part of the question to see
if there was a clue there?
014 Yes - yes - urn - I often do that - it seems to help me sometimes
- yes - we've done this recently but - can't remember - em - I revised
it for the exam as well but I can't remember - er - urn - thinking of
something else now - em - permutite - that seems to come into it
as well - permutite em - permutite - sodium and calcium are right
there - I definitely ? [unclear] sodium and calcium - calcium
carbonate - calcium hydrogen carbonate - or bicarbonate - erm - tch
- [mutters] - I'm leaving that out - I should know it actually -
8(c) 014 [Reads aloud] - er - something to do when - you heat it - in with
water or something - react with water - hot water or something -
hydrated - oh what does that mean - does that mean it's got no water
in - ? [unclear] or is it in water - I'm not sure - I m stuck
- I shouldn't art you - lEx „courage, to have a go without help] -
yes - the questions are all on the .... topic so I', all tight there
I know they're sort of on the sa.e few P«g*= °f •» b°°k ' —pages but 1 (unclear] - hydrated sodiu. carbonate - u. - actually - this actual part - re.ind. of boredo. because 1 didn't like doing
it - er - let .. see - c.lclu. - It's 3«« t.vol.ing around - we did
- A106 -
- the part of the book where we did sodium, clacium, zinc, lead, iron
- and another one but - no just that - we did them all separately
- doing them separately and a couple were connected up - things like
that - em - ca' - no it's definitely sodium something - hardness of
water - chemical test - [we've done?] a table - I'm sure it's
something to do with - reacting with water - when it's heated or
something - erm -
Ex What makes you think that?
014 - well we did a table at the bottom of one of the pages - the
bottom right hand page of the book - I can definitely remember it
- it was there - and we did - how to distinguish between sodium
hydrogencarbonate and hydr - sodium carbonate - and er - I can
remember there's one definite difference - I can just picture it but
I can't put the letters in
Ex You think it's something about putting them in hot water you said?
014 Yeah - something to do with hot water - don t know why
Ex Can you think of what sodium bicarbonate's used for at all?
014 Well I know - I know my mum uses it
Ex Doesn't give you a clue?....._ L,.i, i-hat..... [but when Ex asks014 I'll do number 9 so I can go back to that I
, • „„„h oure it's used to soften waterif a breakthrough was immanent].....c Jnn'i know whv - seem to put it in cooking orfor some reason — don t Know way
something - ..... [agree to go on to 9]
9(a) 014 [Reads aloud] - alkane - definite - we're doing that now so
all right - I'm sure it's alkane - yeah - definitely - that's just
those little diagrams I can remember now -
_ ti ,,.i i pu molecules come into it there 9(b) 014 [Reads aloud] - em - wel H2
- A107 -
I'll just draw CH2 - C - H 2 - urn - the C3 puts me off - I remem'
I always - usually C2 - [Ex explains that propene is probably not
familiar but 014 mentions propane and Ex refers also to ethene].
014 I'll just have a go - er - [draws silently] - urn - I'm a bit stuck
- sems to be triangular for some reason - I know it doesn't seem the
right shape - er - urn - bit stuck on this - I can remember seeing
CH2 molecules - so it's C in the middle and two Hs sticking out - and
they were all joined together in long lines - but I - I've not met
propene -
Ex How you - can you remember ethene?
014 Ethene - ethane - oh dear - er -
Ex What is the difference between ethene and ethane?
014 - the number of hydrogens - I can't remember which it is - erm
- ethene - CH^ - CH^ -
Ex That's ethane
014 Ethane - ethane it's CH2 CH2*
Ex That's right - this one is like the - ethene - the CH2 CH.,
one - do you remember how the carbons are joind in ethene?
014 Ethene - yeah - they’re just straight like that - erm - C or line
C - but I think there's more than one line - I get mixed up with
ethene and ethane ’cause they’re really very near to each other -
the names and..... erm - we've got a test after dinner!..... er
- I think it's C line C - it's C C, C and Hs like that - I'm a
bit stuck - [I'm doing a complete one?] on the right hand side - ?
[unclear] could be like that actually a straight line - and Hs coming
off there - but I'm sure it's not completed at either end [seems to
be assuming valency of C is 4] - er - I think you have to finish with
a CH3 molecule actually - because you'll have to have - yes - because
that's got 4 coming into it -
- A108 -
Ex That's the carbon's got 4 coming in?
014 Yes - I'll leave it at that though - 'cause I'm not really sure
about that - I think that's wrong but I can't do any better - I might
as well go on to the next one - [concluded owing to lack of time].
TAPE ENDS
PUPIL 016 - TRANSCRIBED PROTOCOL (TEST 03)
1(a) 016 [Reads silently] - two gases - so - there's two volumes of one
and one volume of the other - oxygen at the anode - hydrogen at the
cathode.
Ex Right now you've told me the answers - would you like to write
them in - and er - can you remember how you got those?
016 - I just seem to remember the experiment - 1 can picture it in
my mind - the - negative - ions are attracted to the anode - positive
ions are attracted to the cathode - er -
Ex - but you weren't thinking about that when you said the answers
oxygen and hydrogen?
016 No - I just got it in my mind you know - keeps recurring
1(b)(i) 016 [Reads under his breath] - oh - I think there's twice as much
of one gas as the other because in the formula - er - which gas is
it - there's two volumes of hydrogen - I think - er - ? [unclear]
the electrolyses of water - sulphuric acid - H ^0 so ? [unclear]
- that appears to be the oxygen - it makes it twice as much oxygen
in the formula -
Ex Yes? -
016 I wish it was hydrogen - (that there was?) two volumes of but
I can't see any reason why it should be - H2S04 [whispers] - ah the
the SO. - no it is the oxygen there's four of isn't it so it s could4
be that some of the oxygen’s turned into - water - and ? [unclear]
less hydrogen but -
Ex I can sort of hear the wheels turning silently there - but you're
not getting anywhere.....016 No I'm not getting anywhere really - 1 thought it was hydrogen
but I can't see any reason why it should be hydrogen, it all seems
to point to oxygen -
Ex I see -
I l(b)(ii)
>
[ U c ) ( i )
016 - think I'd better leave that one and come back to it -
016 [Reads softly] - er well - it could be that the sulphuric acid
isn't - 100% pure - so to speak - it'Id be the impurities that affect
the reaction - or there are impurities on the electrodes - the
impurities on the electrodes I think
Ex [tries a hint for part (i)] - urn dilute sulphuric acid doesn’t
only contain sulphuric acid - what else does it contain?
016 Water.
Ex Right - does that help at all?
016 Yes - the - ratio of the atoms in the water is two hydrogens to
one oxygen -
Ex That would be the way round you thought it should be would it?
016 Yes - ? [unclear]
Ex Why do you think it's the water that's electrolysed and not the
sulphuric acid then?
0 1 6 - 1 just considered it part of the sulphuric acid - somehow
..... [016 confirms what he has said before without adding anything].
016 [Reads under his breath]..... well, if you increase the
concentration there are more ions - to be attracted to the electrodes
- so I think the - amounts of the gas given off - they'Id increase
- in proportion to the concentration - 's more of them -
Ex - that sort of came to you more or less straight away when you
- when you read it?
016 Yeah - I think so - so I'll write that down [does so].
- Alll -
)(ii) 016 [Reads under his breath] - usually increasing temperature speeds
up the reaction - er - but it could - I think that might have the
same effect as concentrating it because you'Id be driving off some
of the water - increasing the temperature - erm
Ex Try to do your wondering out loud if you can -
016 - well if it does drive off some of the water - the sulphuric
acid's becoming more concentrated - so I think it'Id be the same
answer as for (c)(i) - the quantity of gas would be greater at both
electrodes - put that [writes].
1(d) 016 [Reads softly]..... well I think this is to do with the electrons
- in a copper wire the current's conducted by the - movement of the
electrons - but they're not permanently flowing round - it’s er - like
a vibrating motion - that passes the current through - but with the
dilute sulphuric acid the ions are act' - physically moving from one
elec' - from the liquid — to the electrode
Ex You're quite right - how did you remember that? - have you -
answered a question like this before and you remember the answer
or - ?
016 Well the - I can't remember doing about the electrons in the
copper wire in chemistry but we did it in some detail in physics -
Ex Yes -
016 - it just of came straight away -
Ex Yes - fair enough - [016 writes] - so you remembered it in two
it's if you like - one bit about the copper - which you got from your
physics - and one bit about the.....
016 Yeah -
Ex Yes - OK well that's fine.
016 - the actual tables, you know for the ions - which are attracted
- which get discharged..... [writes answer]. [Ex encourages].
- A112 -
2. 016 [Reads softly] - oh - the ammonia's NH3 - that's the gas - it's
NH - the carbonates CO,. - the valency of the ammonium group is 1 -
the carbonate group - 's 2 - (NH4)2C03 - or is it - ? [unclear] -
carbonic acid's H2C03 so the carbonate's valency 2 - the group - NH4
is 1 - I'm sure it's got to be NH4~ twice - CO^ [016 agrees he has
tried to memorise tables of valencies - "parrot-fashion more or
less"] .
2(b)(1) 016 [Reads softly] - er - well the test for water is - well from blue
cobalt chloride paper turns red - but urn - I think there'Id be the
problem of the urea also being in the solution - but I don't know
whether that would affect the blue cobalt chloride paper - I shouldn't
think it would - 'cause if there's water present blue cobalt chloride
paper should always turn red - so - I'll put that - [writes]. [Ex
establishes that 016 does not do biology and he volunteers that he
has not come across urea before].
2(b)(ii) 016 [Reads softly] - covalent, that's the bonding in it - er I think
I'Id need some ? [unclear] valency - yeah - the full structural
formula - urn - covalent - or double - covalent bonds so - can't think
of the formula for urea at all - oh it's - given the formula - NH2 -
CO - the NH2 group I've never come across before - NH2 that s
nitrogen and two hydrogen atoms -
Ex You can draw if you want to [points out back of previous page for
rough work].
016 - so nitrogen and two hydrogen atoms [drawing] - so that's
nitrogen's a valency of three so that s one er bond
still - CO - two coming off - two CO two s - ? [unclear] C02
just CO - CO - that's carbon monoxide - ? [unclear] carbon
covalent bonded - [Ex asks to speak a little louder] - so it s one
- A113 -
left from the nitrogen - carbon's valency 4, oxygen 2 - no that's
two left over from the carbon - so we'Id have two different groups
bond together - the nitrogen bonding to the carbon - erm - the
hydrogen's on the nitrogen still - stuck up - there's two C - the
oxygen's still on the carbon - erm - got a problem there's another
three - ah - it's two molecules of NH2 aren't there - so - the other
nitrogen molecule would --- chain molecule like that [has sketched
correctly though showing the C-0 bond single] - yeah - I think that'll
have to be it - I ’ll draw that in..... [draws and speaks] C - an
oxygen group - an oxygen atom - er - *s got nitrogen each side of that
- I don't think the size is really important - two hydrogens on the
nitrogen - erm - that's two groups - ? [unclear] another NH2 molecule
- check it - 's 2 - one left - one - 's double - yeah it's covalent
so that's right - that's it -
Ex What were you checking then?
016 I was just checking that I'd got - with the valencies of all the
- the elements - whether all the - bonds were used up - or whether
there were any spare -
Ex - so what are the valencies of each of them there?
016 Well carbon’s valency 4, nitrogen's valency 3, hydrogen's valency
1 and oxygen's valency 2 - I don't think there should be any double
covalent bonds in it at all - because you've got - the one, two, three
there - and the same there - and two three, four there
Ex I see — you're counting that [the C-0 bond] as two
016 With the oxygen.
Ex Yes - 'cause the valency's two -
016 - the valency's two yes - so you use two on that - .....
3(a) 016 [Reads very slowly and softly] - manganese(IV) - that’s Mn02
formula - so it's Mn02 - plus hydrochloric acid which is HC1.....
- A114 -
[tries to work it out from an equation on scrap paper] - what's it
give? - name the gas - well - could be hydrogen or oxygen - ?
[unclear] - er what’s the chemical test for oxygen - oxygen - oh dear
- oxygen - no..... what’s the test for hydrogen -
Ex Why are you trying to remember these tests before you've decided
which it is? -
016 - trying to equate the two - see which would be more likely
Ex I see - you hope you might get a clue from remembering the test?
016 Yes - er - don't think manganese chloride would be the gas - don't
think it can - 02 - work the equation out properly - Mn02 + HC1
you'Id get - so if it's hydrogen it's got to be H2 - ? [unclear]
the molecule of the gas - that'll leave you with - oh - if you have
hydrogen there - where does the oxygen go to? - so it could be water
involved somewhere in the reaction - so if you get - you can't have
manganese chloride and water because there'Id be no gas unless the
manganese chloride was the gas - the oxide was - yes - the manganese
chloride was the gas - er - seems unlikely though when there’s oxygen
and hydrogen in the reaction ~
Ex You don't remember this reaction of managanese(VI) oxide and
concentrated hydrochloric acid?
016 No - I don't remember doing it at all - ..... [agree to move ]
3(b) 016 Iron(II) sulphide - it's iron's valency 2 so it's FeS, sulphide’s
valency 2 - reacts with dilute HC1 - it's er - write the equation
[writes on scrap paper] - FeS + HC1 er - name the gas - em - I think
iron(II) chloride would be produced - so that leaves you with
hydrogen - oh - I think there's a precipitate of sulphur - and also
the gas is hydrogen - so - I don't need to balance the equation
because it's not asked for - er - name of the gas - is hydrogen -
- All5 -
the chemical test for hydrogen - 's the lighted splint put into the
test-tube of hydrogen or the gas jar or whatever - and pop -
Ex How do you remember that one?
016 um - just done it for so many reactions - it's just sort of
implanted in me -
Ex You remember it from what? - having written it down so many times
or from actually doing it?
016 Well - both -
Ex OK -016 [Writes answer] [016 unable to account for earlier failure to
recall H2 test under part (a) when Ex queries this - however Ex
mistaken as it was 02 test he is fact failed to recall!].
3(c) 016 [Reads slowly aloud] - ah I think this is one of the laboratory
preparations - I can picture it in my mind - the flask - tilted
downwards - is it the - calcium hydroxide - that's Ca(0H)2 - calcium
is 2, OH group's 1, -Ex That sounds like you remembered the formula complete for that one
anyway•016 Yes - ..... - ammonium chloride - 's NH.C1 - I've got a feeling
this is the preparation for ammonia gas - er and the
hydroxide is slaked lime - I remember it in the reaction - so - s
ammonia - [writes] - chemical test for ammonia - er - can picture
this - you apply the stopper off the concentrated hydrochloric acid
bottle - and the fumes - you get white fumes of ammonium chloride
because of the reaction between the ammonia and the hydrogen chloride
gas given off the stopper -
Ex Yes - you remember seeing this do you or?
016 Yeah - so the chemical test [writing] - apply the top
concentrated HC1 bottle and white fumes of ammonium - ammonium
- A116 -
to (a) as chlorine so thatchloride would be seen. [Ex gives answer
part (d) can be attempted with all the previous answers].
016 Oh yes - I remember.
3(d) 016 [Reads aloud at normal speed] - well - which of these gases
it could be one or more [note contrast with most solvers] - consider
the chlorine - urn - a reaction in which chlorine - chlorine gas and
- I'll just write it down it's easier - sulphur dioxide gas - I think
there's water - [writing an equation on scrap paper] - in the reaction
- you place water in the bottom of the gas jar - at the beginning
before you put the gases in - erm - get a deposit of sulphur - um
- Cl - er - hyd' (if it's an?) oxidising agent - what'Id be oxidised?
- H20 - would be reduced - er - ? [unclear] would be oxidised - that
can't be the right equation [has written Cl2 + SO 2+ H g -» S ]
- I can't see anything there that could be oxidised - Cl 2gas -
hydrogen sulphide - formula H2S - [writes Cl2 + H2S] - oh of course
- oxidation doesn't necessarily mean - addition of oxygen - loss of
electrons also..... just trying to think of one for the loss of
electrons - um - ? [unclear] chlorine in the equation - it's got to
be chlorine gas - Cl2 - 'cause of a molecule of chlorine in the gas
- um - [mutters] - I can't think of a reaction in which electrons
are lost - ? [unclear] - the reaction's with iron chloride - that
wouldn't count because chlorine’s already an integral part of - iron
chloride - um - I'll leave chlorine and go on to the - the next one
- that's hydrogen - er well - gain of hyd' - loss of - loss of
hydrogen can also be oxidation - concentrate on hydrogen anyway for
now - so if you lose the hydrogen - well that won't count because
hydrogen's got to be on its own to start with - em - oxidising agent
- gain of oxygen - hydrogen - ? [unclear] I think of something else
- involving hydrogen on the left hand side of an equation - oh - go
- A117 -
on to ammonia - er NH3 - oh - I think I'll have to leave this -
..... [question 4 is omitted by agreement with the teacher].
5(a) 016 [Reads softly and slowly] - neutral atoms - that doesn't seem
to ring a bell at all - number of electrons - 7 - so that means -
I'll read the other part first see what they want - oh well - an
isotope - is an element - an atom sorry - with the same - same number
of protons in the nucleus but a different number of electrons -
different number of neutrons - so ? [unclear] see - which atoms are
isotopes - it doesn't say which atom is an isotope so there's more
than one - the same element - right - er - looks - looks for (one?)
with the same number of electrons, that will give you the same number
of protons - for the same - to give the same atom - so it’s M and
Q - let's see - the mass number - well the atomic mass is the sum of
the number of protons and neutrons - it's 36 in that case - and
40 is that case so it's got to be M and Q
5(b) 0 U [Reads aloud] -this is going to be difficult I never have
understood the periodic table - which two elements are in the same
group - I'll skip that one and go on to the next one.
5(c) 016 [Reads aloud]- now - what's a halogen - ? [unclear]something to do_ ',not so long ago - urn - halogen [very softly]
with salt hydrolysis - that keeps coming into my head - halogen -
er - it's got to be a different - ? [unclear]
Ex Let me try a slight hint - halogens are a family of elements in
the periodic table - does that help?
016 - family - .6 It could b. the - tho noo - root - the very .t.bl.
- er - elements - they're just the rate gases In alt - no I think
I'll leave that and go on to part (d).
- A118 -
Ex well - well let me tell you what the halogens are because I think
you could probably tackle it if you once decided what the halogens
are - the halogens are fluorine, chlorine, bromine, iodine that group
of elements -
016 I'. s u m » (unclear) halogen - ^lorlne * Iet'S
a loot at the ...a numbers lift - I think I can remember
chlorine - 28 - 36 - chlorine - the valency', the nu.ber of electrons
in the enter energy shell - for for chlorine th.fld be 1 - ,o - I f .
2 in the first one, 1 in the second
Ex Try and keep on aloud.0 1 6 „ - ..... let's give up on that. [Ex falls to nudge 016 into
continuing] .
d) 016 [Reads aloud] - so I’ll look at those two - X is - 19 electrons
L is 16 - it all depends on knowing the atomic - ? [unclear!
weight, of the elements - I »•• » I d that we'd never need to learn
these - they'Id always he give« - ~ - there's got to he some »ay
of working it out - derive a formula for the compound formed -
electrons is 19 - so i f . 19 proton, and 21 neutron. - proton, -
(no.,) think of an element with that - 19 - protons - 21 - neutrons -
Ex ho you remember ho. electron, are arranged in the atom - that might
be a way of getting at it?
016 Ah well - number of electrons.....
jx You might be able to get a valency for the t [unclear] -.ha inner valency shell - that’s
016 So for X, there’s 2 electrons in,, nn to 19 - there’s 8 [writing] - that’s a a 2 - they've got to add up to. _ o _ that's a maximum for the third that
maximum for the second - 8
18 - t's got to be 1 - 2, 8, 8, 1
- A119 -
Ex So - do you know the valency of X from that?
016 - er - valency I - so it's got to be an element with a valency
of 1 - and there's quite a few possibilities for that - er — valency
of i - I think the chances are it's a non-metal - so -
Ex So you're trying to work out what element it is are you? —
016 Yes.....
Ex - because - in the question it says you can use the element at
the top of the column to represent the element - I think they'll be
quite happy for you to use an X in the formula - when you've found
its formula with L - it isn't really necessary for you to work out
what it is.
016 Oh - right.....
Ex Now you know its valency - can you find the valency of L and then
..... ?
016 ..... so that's - 2 for the inner valency shell - 8 - er - 8 and
2 is 10 - number of protons is 16 - 's always the same number of
electrons as protons in the atom - so that leaves 6 - ......there s
got to be 6 in the outer shell - which makes 16 - so those are the
two elements we've got - 2, 8, 6 - er - 2, 8, 6 - what will be the
reaction? - ? [mutter] - X - bloody hell [under his breath] - got
2, 8, 6 - how can I link the two -
Ex Well, can you get a valency?
016 - the valency of L is 6 - the valency of L is 6 because that's
the number of electrons in the outer energy shell - ? [unclear]
valency of X - valency of X was one - so that's - X - if I write it
out it'll be easier - X got a valency of 1 - so the final formula'll
be L - X to the - that's got a valency of 6 - you've got to have 6
L - 6 Xs for every L - so it could be LX to the 6 - the final -
compound. [016 agrees with Ex that his problem was not any lack of
information but knowing how to tackle the question].
- A120
016 [Slowly starts to read aloud under his breath] - "with stirring
an excess of iron filings - a solution of copper(II) sulphate - I'll
write this down as I go along - it'll be slightly easier - that's
er - iron(II) sulphate - copper(II) sulphate so that's Fe - CuSO^
which is copper sulphate - in water - I think you can forget the water
- a reddish brown precipitate was formed and the mixture was filtered
- well it'Id be easier first to know what that er - filt' the -
precipitate was - it's reddish brown - er - 's so many iron - 's got
to be iron - sulphates - trying to think of a table for the salt
solubilities - they're all soluble except calcium, lead - barium
so it's not a precipitate of iron sulphate - a reddish brown
precipitate - er - iron(II) -
Ex You're just reading the first bit again - yes?
016 Crystals of iron(II) sulphate were prepared as follows - excess
of iron filings was added - the iron filings is just iron - so it's
Fe - a little at a time with stirring to a solution of copper(II)
sulphate - CuSO^ - in water - a reddish brown precipitate was formed
- perhaps if I wrote the equation and put water in it - that would
help me - 1^0 -
Ex Now you've written Fe + CuSO^ + 1^0 -
016 Yes - reddish brown precipitate was formed - I must read the rest
of the question - see what you do with those - the mixture was
filtered - that would give you just your precipitate - the filtrate
was evaporated - taking all necessary precautions - what precautions?
- that seems to indicate there's something special about it - until
a saturated solution was formed - filtrate was evaporated that
the - reddish brown precipitate the filtrate - till a saturated
solution was formed - don't see how that can be - the filtrate was
evaporated - filtrate - the solution was then cooled and the crystals
- A121
were filtered off - and dried - it seems just a typical salt prep'
so er - it's whether I've got what a filtrate is correct isn't it,
so - the filtrates what's filtered out of the precipitate - saturated
solution - what's filtered out of the filtrate - could be - so I'll
look at the equation - er - sulphate - iron sulphate's - I'm sure
it must be a precipitate - but - no it can't be because if you - you
fil* - you evaporate the filtrate - that's from where you'll take
the crystals - so it's nothing to do with the precipitate - er - so
what you filter out must be FeSO^- valency of the iron is 2 - sulphate
er - so what else is produced besides the iron sulphate -
reddish-brown precipitate - if it was copper it wouldn't be just that
- it's got to involve copper - what copper salts are insoluble
copper-hydroxide’s not - not an alkali - copper hydroxide’s insoluble
- oh yeah - if it's copper - yes this - this water - ? [unclear]
copper sulphate in water so there's water present so - filtrate would
be FeSO,- this is what was produced and the reddish-brown
precipitate would be Cu(OH)2~ copper hydroxide - er -.....
Ex You haven't in fact started looking at the questions yet have you?
016 No - I'm trying to get a full picture in my mind of the whole
..... the solution was then cooled and crystals were filtered off
and dried.
6(a) 016 [Reads aloud] - well it’s got - to make sure that something on
the left hand side of the equation's used up - before you start
filtering - why was an excess of iron filings used - well let's see
what we've got - copper sulphate in water - I should think tha
be just to make sure that all the copper sulphate’s used up - to make
sure that all the precipitate possible's been obtained from the
sulphate - I think that's the answer [writes].....
- A122 -
jgfii
jtMKi
fWs
6(b) 016 [Reads aloud] - well - if it’s filtered off it’s got to be the
red-brown precipitate so going back to the equation I wrote down -
must be copper hydroxide - copper(II) hydroxide - [writes].
6(c) 016 [Reads aloud] -I'm never very good at these oxidising agent
questions - which of the substances used - so we've got to look at
what was used again - iron - see what was oxidised first of all -
the iron sulphate was ox’ - the iron was oxidised - because it gained
oxygen in the form of the sulphate group - er - so that excludes -
what oxidised it that's the next question - the - copper sulphate
it would appear - ..... it must be the copper sulphate - [writes] -
6(d)(i) 016 [Reads aloud] - oh - because of the nature - what’s special about
iron(II) sulphate - er - could it be something about the temperature
at which it turns to a gas - no - no I can’t see that really - er -
iron(II) sulphate - or does it - does it react with the - the water
vapour in the air to form something else - that seems to ring a bell
- what’s the word - deli - deliquescent - I’m going to have to put
that because I can’t think of anything else - so - the isolation from
air's the answer [writes]
, r . .up isolation from air - it's got6(d)(ii) 016 [Reads aloud] - [repeats] - the isoiat
n ...m _ t - h a t seems to be too much of to be placed in some sort of vacuum
a problem to cope with - to obtain it - so that indicates that the
last part was incorrect - seems to - looking at this question now
- again - picture in my mind - a copper funnel containing hot water
and passing the - the iron sulphate through a gauze within it and
collecting it at the bottom of the funnel - can t seem
the details of it though - 1 [unclear] - precaution it g
be something about the iron(II) sulphate involved with the temperature
if that's the case -- A123 -
W i - .....< '
Ex OK - we’re getting a bit bogged down in that - move on to part (e)
for the moment eh -
6(e) 016 [Reads aloud] - [re-reads aloud] - I see - so you have to know
quite a bit about part (d) to - form an answer to that - .....
Ex No - you don't need to know anything about (d) for the answer to
that - it’s nothing to do with the precautions -
016 -explain why there is a difference between the actual yield and
the calculated yield - [reads again under his breath]..... the
balanced equation -I'll write the balanced equation -
Ex Well - do you know how you would set about calculating the yield
from a balanced equation?
016 No - .... [it transpires that 016’s class have done no. Vip little idea of what is meant byquantitative work as yet and he has n t u e xu
"calculated yield" - the question was thus left at that].
016 [Reads aloud slowly] - « «'• a “ ‘1C leVel “doesn't tefet to the gaining of oayg.a - the - the loss of hydrogen
- that's nothing to do with the ato.lc structure really - I think
- what this IS looking for - I f the - It Involves the electrons
themselves - I think er - define okld.tlou - It's not reduction I
think - -hat this 1 . - I f the loss of electron, In a chemical
reaction - so - I'll write that down -, from a text book or writing
Ex You remember that from learning
it in your note book or what?. c . M e nrrurs we put an arrow across
016 Well the reactions we do if th
with - you know - L - we make it leo or ger -
Ex Yes.....
- A124 -
7(b) 016 [Reads aloud slowly] - if this is referring again to leo and ger
- Um - Fe - that must mean Fe three postive - I've never seen a symbol
like that before but I take it that's what it is - er - plus - H -
er - underline the substance which is being oxidised - the H - it
must be hydrogen - er - it goes to Fe2+ - if it goes to Fe - if
it was 3 positive before - one positive charge cut down so it's got
to be the gain of an electron - so that's got to be reduction I think
- the H positive - to make it positive - negatively charged electron
must be lost so it's got to be the hydrogen that's - oxidised -
[underlines the product of oxidation H ]
Ex It's the H+ ion that's being oxidised is it?
016 Yes - (b) - er (ii) [reads equation aloud] - let’s consider the
copper first - 2 Cu there - so it's not got a charge - so that's the
atom - goes to Cu - 2 positive iron - so it’s gone to 2 positive -
it must have lost electrons - ’cause if it gained them it - would
acquire negative charge so - that’s reduction - ger - gain of
electrons reduction - Br2 goes to 2 Br negative - 2 for - the Br2
negative ions - so if it's 2 Br negative - ah - I think I might have
been doing these wrong - H positive - loss of electrons is
- leo - so that one’s right - I've been tackling the first part of
this incorrectly - 2 Cu goes to 2 Cu positive - it's gone from no
charge - neutrally charged - to 2 positive - so that must have lost
electrons - it's leo which is loss of electrons - in oxidation so
it's got to be that I think - I'll just check the bromine to make
sure - Br2 - 2 Br negative - it's gone to negative - ? [unclear]
gone to negatively charged must have gained electrons so - it must
be the 2 Cu 2 positive ion - [underlines £roduct again] - part (c) -
7(c) 016 [Reads aloud] - don't seem to recognise that one catalyt
oxidation - ? [unclear] - I've come across catalytic - catalytic
- A125 -
cracking -and not the - ? [unclear] - anything to do with it - don't
see as - it's oxides anyway so - sulphur(IV) - sulphur(VI) 2 - of
two in the valency - I didn't know sulphur could - ? [unclear] - like
that er - I'm going to have to leave them two - I don't
understand.....
Ex Sulphur(IV) oxide is sulphur dioxide S02 and sulphur(VI) oxide is
sulphur trioxide, SOj, does that help?
016 - it's the catalytic oxidation I don't understand - I've never
come across it before - the term before -
Ex Yes - does it - even though you haven't heard it before what does
it mean?016 I seem to remember - picture in my mind - the preparation of
sulphur trioxide - er passing sulph' - I remember how it’s collected
- with ice and salt - ..... in a flask - er - preparation of sulphur
- oh it's passing - oh passing - first prepare the sulphur dioxide
- pass it over a vanadium pentoxide catalyst
Ex So it has a catalyst - is it oxidation?
016 - er - catalytic oxidation - S0 2 to SO3 - yes - yes it is 'cause
gained oxygen -Ex So ev,» though, oven though you don't kno. the phto.e - it would
016 - yes - er - .....
Ex OK - now what's the industrial process?
016 - industrial process - what's it called - industrial prepa
of sulphur trioxide - urn - it’s not the Solvay process - that's er
- ? [unclear] - er -
Ex What about (c)(ii) - do you know that one?
016 [reads aloud] - reduction of nitrogen to ammonia - ah this goes
from N to NH3 so it's a gain of hydrogen which is reduction -
- A126 -
catalytic reduction of nitrogen to ammonia - N to NH3 industrial
process with nitrogen involved - nitrogen - can't think of any
preparation at all with nitrogen involved - no - I'm going to have
to leave (c)(ii) “
Ex OK.016 I'Id just like to go back to (c) part (i) - all I remember is
writing down the industrial preparation of sulphur trioxide - I don’t
seem to remember giving it a specific name - no I'll have to leave
it -Ex OK - I think we'll have to stop there because we’re running out
of tape.
TAPE ENDS
- Al27 -
pttptt. 017 - TRANSCRIBED PROTOCOL (TEST 031
1(a) Oil [Reads silently] - I do this by taking sulphuric acid - breaking
it down into H positive ion - S04 2 negative - and water - then -
at the anode which is positive something negative's going to be formed
which will be - either S0 4 2 negative or oxygen - the oxygen - will
be the name of the gas formed at the anode - and the hydrogen has
got to be the gas formed at the cathode
Ex Now why did you go for the oxygen at the anode?
017 'Cause that's oxygen er - oxygen will displace the SC>4 2 negative
X think.
Ex Yes - where does the oxygen come from?
017 The water - it's - yeah water
Ex OK - do you know what ion it comes from?
017 - H 3 - 0 positive - 0H3 positive - 0 negative..... [borrows Ex's
pen].....so 1 think - again now which is positive - I think it's
oxygen at the anode and hydrogen at the cathode [writes] - (in fact?)
I'm sure 'cause the next question says 1:2 - ratio - oxygen is in
a 2 : 1 ratio with hydrogen in - ? [unclear] - that s a give a ay
1(b)(1) O H [Reads silently] - why's a 1:2 ratio expected well
usually associate oxygen and hydrogen with water which is H2
the valency of water so that's a 2 : 1 ratio - 's only thing 1 could
think of - [writes] - water contains hydrogen and oxygen in a ratio
of 2 : 1 therefore it is expected to collect the two gases in a ratio
of 2:1. [017 unimpressed by suggestion from Ex re relev
Avogadro's law (which he claims not to have met) and offers no
comment].l(b)(ii) 017 [Reads aloud without prompting] - could be impurities at
. . .r - or a certain numbereither anode or cathode - s possible. ^ „„of a reason why it's not obtained inof electrons might - suggest a
- A128 -
practice - well to be a 2:1 ratio really ? [unclear] - perfect isn’t
that really - got to be absolutely faultless - so anything that -
impurities or what have you - ? [unclear] - won’t you - (no - I'll
have to put that?) - .... only thing I can think of is impurities
at the cathode - and the anode - and that you can't afford a single
mistake really - or - you never - [Ex establishes that 017 would
write an answer and he does so].....
l(c)(i) 017 [Reads aloud] - oh - increase the concentration - it’ll speed
up the reaction - ’cause er - increase in concentation finely divided
particles - or - increasing the temperature - all are pre-set ways
of - speeding up a reaction
Ex I see - you remember this from your note book or something like
that do you?0 1 7 yes.... the reaction - er - would take place much quicker
[writing].
U C )(,1 ) 017 - Increasing the » » « • » « - » a t will »ete.se the speed a.
well - so [writes] - also increase - the speed.....
1 (d) 017 [Reads aloud, - at. you using the saw. - at« you still using the
sulphuric - oh yes - -l«* «sis » think aloud if possible) - er -
[.utter] - I wouldn’t do that I don't think - to be honest - until
possibly the last - ..... l & * » = supple-entaty question about whyc nart ( c ) but with no veryconstant current is referred t P
informative response]•
2(a) 017 [Reads silently]- ammonium’s NH, - carbonate group is CO3
- valency of 2 - so it’s got to be NH, twice CO3 [writes] -
- A129 -
Ex How do you get the valencies - just remember them do you?
017 Yes -
017 [Reads silently] - you could test the water by using litmus paper
- and er - water turns - purple litmus paper - no blue litmus
er - water turns purple litmus blue - or is it blue litmus purple
- water turns blue litmus paper pink - I think that's it - [writes
this]•Ex Are you trying to remember this from something you've done or.....
017 Yeah - last year -
Ex From doing it rather than the notebook -
017 Yes.....
Ex Have you come across urea before?
017 No.... (NH^) twice CO - uh uh
Ex Now what are you thinking about?
017 - trying to work out what the valency of CO is - CO carbon
monoxide is ? [unclear] have nitrogen going to 2 hydrogens - it's
got - NH2 - and you've got that twice haven’t you so - it’s possibly
linked there - then it's a CO - going in somewhere - [has written
N-N-H
H-N-H] CO possibly being linked - what's up there c o 2 CO no
can’t be can it - ? [unclear] 's a double - bit stuck here doing this
- n h2 -Ex Well you're obviously turning something over in your mind can
you tell us what it is?
017 I’m trying to work out - from the formula - how to place it in
the structural formula - I'm trying to work the carbon monoxide into
a formula with the nitorgen and the hydrogen -
- A130 -
■M| ■■■■■i
Ex How do you get the valencies - just remember them do you?
017 Yes -
2(b) 017 [Reads silently] - you could test the water by using litmus paper
- and er - water turns - purple litmus paper - no blue litmus
er - water turns purple litmus blue - or is it blue litmus purple
- water turns blue litmus paper pink - I think that's it - [writes
this] .Ex Are you trying to remember this from something you've done or.....
017 Yeah - last year -
Ex From doing it rather than the notebook -
017 Yes.....
Ex Have you come across urea before?
017 No..... (NH2) twice CO - uh uh -
Ex Now what are you thinking about? —
017 - trying to work out what the valency of CO is - CO carbon
monoxide is ? [unclear] have nitrogen going to 2 hydrogens - it’s
got - NH2 - and you've got that twice haven't you so - it’s possibly
linked there - then it's a CO - going in somewhere - [has written
N-N-H
H-N-H] CO possibly being linked - what's up there - CO^ CO no
can’t be can it - ? [unclear] ’s a double - bit stuck here doing this?
- n h2 -
Ex Well you're obviously turning something over in your mind - can
you tell us what it is?017 I’m trying to work out - from the formula - how to place it in
the structural formula - I’m trying to work the carbon monoxide into
a formula with the nitorgen and the hydrogen
- A130 -
Ex Yes -at the beginning you mentioned valency - do you - know any
of the valencies you need? -
017 Hydrogen’s got a valency of 1 - that means nitrogen - here must
have a valency of - 1 is - 2 - yeah - nitrogen’s got a valency of
2 - [mutter] - nitrogen's got a valency of 1 as it must have from
that [meaning the group containing N?] - therefore CO - has got a
valency of -
Ex How are you trying to work these valencies out?
017 Well I know hydrogen's - the valency of hydrogen’s one -..... so
it's got 2 hydrogens - that makes - its val' - it's got to be 2 -
the nitrogen - so therefore the valency of all that is - (in other
words?) the valency of all that group NH2 - is - do you add them
together or multiply them or what? [Ex suggests moving on to the next
item].
3(a) 0T7 [Reads silently] - this is - this is er - the lab preparation
of chlorine so the name of the gas is - chlorine
Ex Yes - now again there's the answer - where does it come from?
017 I just know that - manganese(IV) oxide reacts with concentrated
hydrochloric acid to give chlorine -..... chemical test er - bleaches
litmus - no er - turns damp blue litmus paper red and then bleaches
it - [writes this] -
3(b) 017_ [Reads under his breath] - er - well iron(II) sulphide that s
FeS, - plus HC1 [writes this] - name of the gas - oh it must give
sulphur - yeah it gives sulphur ? [unclear] - yes it would - no would
it hold on - sulphur - iron chloride and hydrogen - yeah sulphur -
and chemical test for sulphur - er - I don't know what the chemical
test is - I don’t think we've done the chemical test for sulphur have
we - no - 1 don’t know - I don't think we've done any - [Ex asks if
sulphur is a gas]
017 - no - it’s a yellow solid isn't it - ? [unclear] bit of a - ?
[unclear] - I'm good at them ........can't be sulphur - got to be
- they wouldn't trick you they of there's no gas given off? [Ex
indicates negatively]..... trying to see if it’s swapping partners
or what - - oh er - acid plus sulphide gives oh er - hydrogen sulphide
- yeah - we're getting hydrogen sulphide there - it's either that or
- sulphur dioxide - I think it’s hydrogen sulphide - er the chemical
test for it - era - ..... - lead ethanoate I think you use - any lead
ions - lead nitrate er - turns it black -
Ex Now were you trying to remember the properties of hydrogen sulphide
then or were you trying to - remember all the tests you could think
of or -017 Remember all the tests I could think of - it's either that or
it turns pur’ - er - orange manganese - green or green manganese
orange - no 1 think it's - that’s sulphur dioxide - it turns lead
- any lead ions black [writes] - lead ions black -
3(c) 017 Ammonium chloride and calcium hydroxide - that’s - ? [unclear]
- calcium - oh hydroxides are insoluble - ammonium chloride it is
- no - (insoluble?) - the gas must be - ammonium - ammonia - I would
imagine -..... because - ? [unclear] you're not going to make much
sense ? [unclear] - calcium chloride isn’t a gas - ammonium hydroxide
isn’t a gas - that means calcium chloride must be formed - along with
ammonia and water - so I think it’s got to be ammonia -
Ex Yes - where's the water from then?
017 - the hydroxide..... ammonia [writes] - test for ammonia - so
it's something to do with er - - when ammonium chloride is added to
a stopper of the cone’ - concentrated hydrochloric acid - and it gives
white fumes of ammonia - that's a test for it -..... [writes]
"ammonium ions added to concentrated hydrochloric acid gives fumes
arnmnnium chloride •- A132 -
ft
3(d) 017 [Reads aloud] - chlorine - definitely.
Ex Now again you've given me the answer but I'm not sure how you've
got it -017 - ’cause - we've done chlorine in a lot of detail - we know for
a fact it's an - oxidising agent - it says - normally reacts - well
hydrogen sulphide can react as - well - (it acts?) as oxidising
agent and a reducing agent - so ? [unclear] - that would be correct
but that one - I don't know anything about ammonia.....
5. 017_ [Reads silently] - which atoms are isotopes of the same element
[sighs] - well - I’m trying to think to myself what the definition
of an isotope is - because - this is er - isotope er - different
number of - different number of - protons isn’t it - in the nucleus
- so which atoms are isotopes of the same element - I don’t think
I'Id do this one to be perfectly honest but
Ex Well have a go, but don’t waste too much time if you’re not making
progress.017 -..... looking for some connection between the figures - is that
number of electrons - in the outer shell - number of - or total
number of electrons - (if its total?) - so that means - that's 2,
4 _ 2> 7 _ 2 , 8, 4 - 2, 8, 6; 2, 8, 10 - [writes these on the table
and silently adds Q 2, 8, 10 and X 2, 8, 11] - mass number is - ?
[mutters] -Ex Now what are you trying to do with the mass number now?
017 Well - number of electrons - of J is half the mass number
with L - and M - so ? [unclear) (negative?) anything there - but it
says which atoms - so it obviously means at least two - I Id say L
and M -Ex OK - what do you say isotopes are? I didn t catch that.
017 - substance which has - different number of - protons
nucleus -- A133 - 1
■HMRfck.
Ex I see - yes -
qjj _ i'll have to leave this one altogether.
Ex OK -
017 [Reads silently and rapidly] - why was excess of iron filings
used - an excess is used - so - [mutters] I forgot why an excess is
used now - 'cause you get -Ex Now again - it sounds as if lots of thinking's going on - but it's
not going onto the tape -
017 Yeah - um -Ex You're trying to think back to something about excess are you?
017 Yeah - excess er iron - er - you get bubbling -
Ex You're trying to think of occasions when you’ve come across excess
of soemthing before? -017 Yes - when you get an excess it gives - bubblings - which when
the bubbling stops you know - that the reaction has taken place
? [unclear] the first part of the reaction has taken place - when
the bubbling stops - ? [unclear] you've got your precipitate - you'll
know when to filter it - so you've got to add an excess to - no! no
no no, no - you have an excess to make sure that all the copper(II)
sulphate is used up -
Ex Yes?017 [Writing] yes - an excess is used - to make sure all the
copper(II) sulphate is used up.
Ex You came up with the right idea in the end - now where did you
get it from?017 Well you see I racked my brains - why you had to use
for -Ex You've come across another example like this have you.
A134
017 Yes with an acid - yes - erm - acid plus base - gives you
magnesium - no - yes - no acid plus yes metal I think it was -
magnesium.....
6(b) 017 [Reads aloud] - well that - I’m trying to work out the reaction
in my mind - FeSO^ plus copper(II) sulphate - that'll give - [mutters]
- name the substance which had to be filtered off before crystalising
the solution - a reddish-brown precipitate - [mutters under his
breath] -
Ex Are you re-reading the question a bit here?
017 Yes - well it's - iron sulphate and copper sulphate isn't in an
- oh - I'll say iron - plus copper sulphate which is - l'be iron
sulphate - I should imagine - oh it’s crystals - excess iron added
- to a solution of copper(II) sulphate in water - so it's - I think
the copper’s - replac' - displacing the - the iron's displacing the
copper - must do surely - it’s got I think it’s got to be iron
sulphate - just by a matter of logic - I can't think what else what
it is - iron sulph' - the iron goes - iron - to make iron sulphate
- so you’ve got iron is added to the copper(XI) sulphate - in water
- can't see what your iron - it’s copper(II) sulphate ? [unclear]
you going to get rid of the copper(II) sulphate - I should imagine
it’s got to be iron - iron sulphate which is given off - [writes
answer].
6(c) 017 [Reads slowly aloud] - [sighs] - ? [unclear] I’ll just read the
question over again I think - [mutters as he does so] - only using
two substances aren't they [surprised tone] - iron and copper(II)
sulphate - so which of the substances used acted as an oxidising -
it’s got to be one of those surely - and - all metals are reducing
agents - so it’s got to be copper(II) sulphate - [writes].....
- A135 -
6(d)(1) 017 [Reads silently] - er iron(II) sulphate - It’ll be s’ -
insoluble - it’s insoluble in water - so it’ll have to be collected
using an upturned gas jar - I think - I think it'll be insoluble -
definitely - so - 'll have to be collected - [writes] "iron(ll)
sulphate is insoluble - in water - therefore - needs to be collected
by downward delivery" -
6(d)(ii) 017 [Reads aloud] - I've answered that in the other question haven’t
I - now it's - now - I don’t know - how might this precaution be taken - by using an upturned - by using downward delivery in a gas jar -
1-11 have to repeat myself there I think - [writes] by using downward
delivery..... is there something missing - what do you think the
precaution might be - 7 [unclear] - you’ll want to - evaporate 7 -
6(e) 017. [Reads quickly under his breath] - difference in yield - er -
because - you’ve got to try and calculate the point of crystalisation
- and - [interruption] - because calculating the point of
crystalisation - is very difficult - you could even - er - could
filter the mixture - too early - or too - or too late - it’s - got a
- finding it on the point of crystalisation is - it's difficult -
[writes] - it’s difficult for it to know when to stop - to know when
to stop the experiment in order to find the point of crystalisation.
7(a) 017 [Reads silently] - atomic level - oxygen - oxygen, oxidation is
the loss of - electrons [writes]
Ex That’s just a sort of memorised definition is it -
017 Yes -
Ex Any special way you remember it?, - loss of electrons equals oxygen017. Oh yes - L E 0 - loss of oxygen loss
- vpflh - [Ex encourages] -- A136 -
7(b) 017 [Reads silently] - 'cause iron lost electrons [very softly]
Fe - 's copper - being oxidised [writes] -
Ex Yes - now how have you worked that out?
017 Well it's gone from copper to copper 2 positive therefore - it's
lost electrons - or gained them - yeah - or lost electrons or gained
- protons -
Ex You're looking at (i) now are you? -
7(c)(i) 017_ [Reads aloud] - I don’t know [positively] -
Ex If we gave them different names - sulphur dioxide and sulphur
trioxide - would that -
017 Oh er -name the industrial process er - I remember doing it but
I can't remember it - nitrogen to ammonia is er [positively again]
- oh third year - fountain experiment - Haber process - [writes]
- last number of 7 I don't know - number 7(c) part (i)
Ex - You remember doing this as a lab' experiment do you?
017 I remember doing it - no - I remember doing as I was given a
diagram and -
Ex Yes? -
017 - dictated to you -
Ex Yeah - but you can’t remember the name that went with it?
017 No.
Ex Um - why did you miss out (b) part (i) Y°u didn c say anything
about that - you did the second equation, you didn't do the first
equation -
017 Oh I see - yes - it's the hydrogen that's being
Ex Yeah - why did you miss it out - do you know?
017 I thought you had to just pick out ? [unclear] - I thought - oh
- in each of the following equations - ? [unclear] yeah I missed
the question then - [Ex encourages and directs to the next
question]•- A137 -
8 (a) 017 [Reads quickly aloud] - [sighs] - oh I can't remember - it's a
complicated name - no er - or is it - sodium something - sodium
carbonate no - sodium hydrogencarbonate - sodium - no sodium
carbonate I think [doubtfully - but writes it. 017 then goes off
to register and returns]•
8(b) 017 [Reads aloud] - ? [unclear] contains calcium hydrogencarbonate
- ? [unclear] carbonate and magnesium - [writes] - are present to
- er - [has written "calcium hydrogencarbonate and magnesium
hydrogencarbonate are present too"] - something about present and
make - I mean to need - more soap - to lather the hard water - (just
doesn’t look?) -magnesium carb’ - magnesium hydrogencarbonate and
calcium hydrogencarbonate - er - make it difficult for - need more
soap to - make the water lather ’cause they're present - [mutters] -
Ex What were you doing there?
017 thinking of these chemical tests [has left his answer to (b) as
it was] -
8 (c) 017_ - I'm stuck with these to be honest - I don't know ? [unclear]
Ex - well fair enough - but have a go - (c) is in fact not a test
which you're required to know in the syllabus but you should know
enough about the substances to be able to devise one
017 er - sodium carbonate - when heated - won’t break down - but
sodium bicarbonate will - into carbon dioxide, water and sodium
carbonate ~ I think, yeah, yeah
Ex So how would you make that a chemical test?
017 Well - from there two subjects - two objects - substances - heat
both of them - and which one broke - gave off - one - sodium carbonate
gave off carbon dioxide which you test for - sodium carbonate -
Ex How would you test for the carbon dioxide?
017 Lime water -[Ex encourages and 017 writes answer]
9(a) 017 [Reads aloud] -
Ex Now, do you recognise propene at all?
017 No - I thought if it was an alkane it would be C Hg.g
Ex Well in fact you're quite right - you haven't met propene before
.....[discusses alkenes as analogues of alkanes, CnH2n - and with
ethene as first member]..... you should be able to draw a sketch
of the formula for ethene - and by comparison you should be able to
do it.....
017 Single bond isn't it?
Ex Well that’s something you should know - I'm not going to tell you.
017 I'm not sure myself - I think it’s a single bond.... [sketches] -
Ex How are you doing it - you’re writing down 3 carbons in a row are
you?017 Yeah - I think that’s right, I'm not sure - must be something like
that - 'cause you have hydrogen between -
Ex You've only got 2 carbons there have you [has drawn ethane
correctly]•
017 Yeah - oh . CH„ CH - CH2 - that means - that (expands?)
must be ? [unclear] - that's more likely isn't it.
Kc)(i) 017 [Reads aloud] - plastic is it?Ex Well again - work by comparison with ethene which you do know about
- propene's just the next member up the series
017 Ethene - helps to make polyvinyl chloride and polythene
this - cnnot gl». polython...... IB* ..t.bli.he. th.t 017 h,. not
h „ rt of polypropylene but e.ks to continue . « b polyth.n. ...»«>
as the correct answer].
9(c)(ii) 017 [Reads aloud] - self - addition - polymerisation.
Ex That's it - how did you know that - you just remember it?
O n yeah - just remember it so - long chain - self addition.....
9(d)(i) O H [Reads aloud] - hydrocarbon is alkane - so it's - a hydrocarbon
is a - a substance which contains hydrogen and carbon - and can take
the formula Cn H2n + 2 [writes] "hydrocarbon by its name implies
that it contains hydrogen and carbon. It can also - [crosses out]
- it will take the formula" - not enough space here - "Cn H2n + 2" “
9(d)(ii) 017 [Reads aloud] - No - no definitely not.
E, That’. «hat - bee.»., lb do»«'* have the right general tor.ul,.
017 Yes.
tape ends
- A140 -
' '9
PUPIL 018 - TRANSCRIBED PROTOCOL (TEST 03)
1(a) 018 [Reads partly aloud - asks for paper - Ex tells to use back of
page facing the question] - platinum electrodes - sulphuric acid
Ex So - could you say what you're writing down? -
018 - Sulphuric acid - ? [unclear] - the ions - gives 2H
positive ions and SO^ 2 negative ions - dilute - so that - that
contains water - 2H positive ions and OH negative - so that - the
anode - that's positive - so the negative ions - the SO2 and the OH
negative will be attracted but the - the OH negative - you know the
OH negative — er ions will be discharged — the gas
Ex Why the OH ones rather than the S0^?
0i8 — erm - .......are they lower in the electrochemical series?
[agrees with Ex that he knows it was OH anyway] - so it would be
er at the anode - it'Id be oxygen - and - at the cathode - which
you’ve only got H positive - ions - then it'Id just - it'Id just be
hydrogen given off -..... [in reply to Ex’s question 018 explains
a routine he has learned involving a table etc which he applied
in this item].
1(b) 018 [Reads partly aloud] - expected to be in a 2:1 ratio - one gas
- will be slightly less than half the other - erm - er - I think the
- erm - it's the anode - that - er - works the fastest to start with
- er giving off - yes it gives off more oxygen - to start off with
- than there -
Ex Why do you say it's the anode that gives off gas fastest to start
with?
0 1 8 - 1 think that's partly what I've learnt - but I didn't really
- er you know - that's what I've - er - you know sort of seen in the
electrolysis - the - the oxygen starts to come off but er - sort of
got no scientific method to work it out -
- A141 -
Ex You just remember it from seeing the experiment?
018 Yes-018 The - hydrogen starts - slightly slower - well the ions being
attracted - er - why's it expected - er - probably ’cause the
probably 'cause the'Id be more - erm - oxygen ion - er hydroxide ions
present - than the - than the hydrogen ones - I think that'Id be -
er - I'll put that down [writes "higher concentration of hydroxide
than hydrogen ions"]....... [018 agrees he worked back from his memory
of what actually happened]..... to start with - you know ’cause once
it gets going the hydrogen comes off but er - it start - the reaction
- the reaction started off with more oxygen - er - being given off
..... [finishes writing].
018 [Reads aloud] - er - could - could it be - it could be that -
the - anode - erm - the anode sort of isn’t properly set right -
[re-reads in a whisper] - well it could be urn -it could be a different
concentration - it could be - the solution of dilute sulphuric acid
could be - more dilute - than the 2:1 ratio - er - that it usually
gives - but could be more concentrated and then er - you know - sort
of - the ratios would be - no the ratios would be more - more or less
the same - so to speak it - could be to do with the em’ - the weakness
or the concentration of the acid - ..... well - you know er - put er
- the weakness or the concentration of the - acid - you know, the
different concentration of the ions - 'cause if - they Id be
of one that there were the other then it s - you sort of
get more hydrogen than there is oxygen - if there was a loweri tia it- other way round [seems to relateconcentration then you1Id get it the otner way
differential discharge to differences in concentration plus confusing
change of ratio with change of product at an electrode]..... [writes
answer] how dilute or concentrated the solution - no - er the ions, - yeah 1 think - yeah.....
in solution are [repeats].... y _
1(c)(1) 018 [Reads aloud] - increasing it - er - current is kept constant
- increasing - if you had a 2 : 1 ratio to start with - I said it was
the oxygen that's given off 2 parts to the hydrogen - which is given
off as 1 part - then looking at that - probably be a - a higher
concentration of the er oxygen ions being given off - yeah - increas
ing the concentration - er - think I’ll put that - er -increasing the
concentration - increase [writing] of oxygen being given off -
Ex That's 'cause there'Id be more hydroxide?
018 Yeah.....what I'm thinking was - the 1:2 ratio - now I said that
the oxygen would be given off quicker - that'll be the 2 parts.
Ex Yes -
018 That'Id be the oxygen - that'Id be the hydrogen - if you
increase the sulphuric acid the concentration of that - in fact I
was saying it’s the - oxygen that was coming off the most -
Ex Yes -
018 If you increased it there'Id be more oxygen coming off - if you
started off with a 2 : 1 ratio - you know if - the ions ’cause I said
there was more hydroxide ions being given off.
Ex Yes - what would happen to the rate of the hydrogen coming off
then?018 - well that -.....I think that'Id increase as well - but if you
started off with a 2 : 1 ratio then you’Id - sort of like - em - double
the oxygen - and er - double the hydrogen - so you'Id still set -
you’Id still get that er - you'Id still get that greater ratio of
oxygen - er - sorry - hydroxide ions being given off than the
hydrogen -
Ex So you'Id say in fact both gases would be doule in rate?
018 Oh yeah - oh yeah - increase of oxygen - plus increase of hydrogen
[finishes writing].....
A143 -
l(c)(ii) 018 - increasing the temperature of the sulphuric acid - increasing
the temperature - temperature - er - if you increase the temperature
of something you'Id be er - sort of like speeding it up so to speak
-'s if you speed up - a reaction doesn't work very well - you sort
of er - heat it - to speed the reaction up - but er - increasing the
temperature of the sulphuric acid - the - the prob' - there'Id most
probably be er - er an increase again like (i) -..... ah, there'Id
be an increase of - there'Id be an increased both gases - but they'Id
still be - er given up in the 2 : 1 ratio - [writes] - "speeding up
the reaction there would still be a 2 : 1 ratio of the gases .
1(d) 018 [Reads aloud] - copper wire -..... urn - ? [unclear] use platinum
electrodes for the conduction through - dilute sulphuric - ? [unclear]
copper — erm — if you've — you've got the same ions coming — from the
sulphuric acid — copper wire - probably - probably er — will that act
as - will that act as an insulator - no - it's probably the - copper
wire that was conducting the electricity - more than the er - more
than dilute sulphuric acid - [re-reads question under his breath]
does the - er - that must mean that - you're - are you using copper
electrodes? - for - the - conduction through it - or is it -
Ex What do you think?
018 - yes - than that through a copper wire - [re-reads again] - yeah
-um - I think that'Id be that the copper wire - the copper wire'Id -
take - you know make erm — take more current going through it than the
- er dilute sulphuric acid - I'm not too sure of that er - no I'll
put that - I - I - I think you know - if I - you know - come across
that - you know that's what I'Id put..... [writes] copper wire would
conduct the electricity more than the dilute sulphuric acid -.....
- A144 -
2(b)(1)
I 2(b)(ii)
018 [Reads aloud] - ammonium carbonate - that's - hydrogen carbonate -
H2C03 [writes this] - there's - er - hydrogen 's got a valency of 1 -
ammonium's got a valency of 1 so that'Id be - ammonium - NH^ twice -
COj NH^ - (XXj - I don't think - H - l^CO^ - HCO^ - no - that's NH -
NH^ brackets twice - CO^.
018 [Reads aloud] - er - oh what's the test for water - em - oh dear -
test for water - 's er - some paper er - that you can test - if it
was - er - water - oh dear - um -
Ex Are you trying to think about all the tests you know - or are you
trying to think all you know about water?
018 I'm trying to think about all the tests I know - er - I know one
for water - there's some paper you can use - it turns - I think it
turns pink - if the water's given off - oh dear me - er -
Ex How is it you remembered the paper going pink - is that - um from
seeing it done or from reading about it or?
018 That's from biology - er - you know not chemistry..... attached
a piece of paper to a leaf - it was - transpiration - to see if it
was the top side of the leaf - transpired more than the - underneath
side - that - test for it you put - whatever the paper was you put
underneath - I just can't remember the name of it - no - oh dear
[mutter] - .....
018 [Reads aloud] - structural - that's er - formula for urea NH., -
C03 - I mean - 's - um - draw - so that’ll mean - draw circles - and
then - the lines like that or - just to write the - er - just to write
the numbers in - N2 - urea - try to draw its full structural formula
- draw -
Ex You're worried about what it is they want there?
- A U 5 -
018 Yes - em - it say's try to draw - I think it must mean - you know
- put your C02 there - and then you have your - is it double covalent
bond [draws CO = ] - or just a CO - covalent compound [reading]
- twice - CO - ? [unclear] 's all covalent bonds - NH2 - covalent
it must be - CO - double covalent bond - HN2~ ? [unclear] draw a
covalent bond - or is it - no that's right - ' s - it's a - it’s a
single covalent bond - 'cause seeing as it's - NH2 brackets 4 if it
was a double covalent bond and it's - NH2 brackets 4 C02 if it’s
double covalent bond - [has drawn NH2 - CO - NH2].
[Ex finds 018 unable to recall test for water]
3(a) 018 [Reads silently] - following reactions - manganese(IV) oxide
- with hydrochloric acid - that's the test for - that's the - that’s
the one for - er - chlorine - that's lab' prep' for chlorine - surely
- ....er [writes on scrap paper] - Mn0 2 plus - oh yes that’ll be
4 HC1 [agrees with Ex that the 4 is memorised - then "rationalises"
it correctly] - Cl2 er - Mn02 - MnCl, - 'll be plus H20 - 2 H20
that’s 4 hydrogens on that side [agrees that he is balancing equation
to check up on answer and elaborates on this - want’s to make sure
everything is accounted for - claims he would do the same in exam']
- chemical test for chlorine - oh dear me - er - chemical test - er -
urn - chemical test for chlorine - chlorine - er - [can’t remember
it] 7 [unclear] - chemical test for chlorine [taps pencil] - dear
me - oh ? [unclear] the book - ' 1 leave that one for a minute -
probably be able to remember the chemical test in a minute -
3(b) 01^ Xron(II) sulphide - FeS - iron(II) sulphide [writes] p
• 1 be - hydrogen - hydrogen sulphide - hydrogen sulphide - hydrogen
sulphide erm - hydrogen - oh - or er - hydrogen - name the gas -
- A146 -
hydrogen sulphide - chemical test - chemical test - oh er - something
- is it something nitrate - er - something nitrate - er - oh dear
- chemical test - nitrate [whispering] -
Ex Now you keep saying chemical test - are you thinking through all
the chemical tests you can think of?
018 Yes I am - em - oh dear - I do know it as well - you know it s
there - but I - just er - it won't come - er - some nitrate - er -
[mutter] - potassium - [mutter] - ..... oh I'll have to - sort of come
back to those when I've - done -
3(c) 018 Ammonium chloride - that's N - I'm writing its formula - NH4C1 -
heated - some catch - plus Ca - OH - ah oh - it'll be ammonia - the
gas - NH3 - you'Id have a - a hydrogen - so that must be H20 - plus
CaCl2 er - oh dear - name of gas ammonia [has written equation on
scrap - now fills in name on answer sheet] -
Ex What's the oh dear about?
018 Ammonia - oh yeah - that's the chemical test again - these
chemical tests - ..... ah er - chemical test for ammonia - [Explains
with asides to Ex that he is..... ]......just trying to think back
- you know - what chemical tests we've been over - hydrogen sulphide
- seems to be really familiar..... [Ex encourages]......chlorine
hydrogen sulphide - .....Ex Well tests often involve putting a piece of coloured paper in
something.....018 - potassium - er - minds gone blank for chemical tests er - [agree
to leave the tests].
3(d) 018 [Reads aloud] - oxidising agent - I must write these out p
plus - H2S - plus - ..... yeah well I'll finish some of the equation
and I can see - which ones are - oxidising agents - by seeing er -
- A147 -
which ones - little er - loss of hydrogen is oxidation - you know
it's a reverse of em - oxygen - whereas the gain of - gain of oxygen
to a substance is oxidation - whereas the gain of hydrogen to some
thing is reduction - and the other way round 'cause hydrogen’s
chemically - opposite to er - to oxygen - [returns to H2S equation]
_ S - 2 - right [has correct equation] - erm - so gain of hydrogen
is reduction - ..... erm - 's - er - oh dear - which of these gases
normally reacts as an oxidising agent - oh dear - gas - [mutters]
- chlorine er - 's loss of hydrogen - oxid' - gain of hydrogen - is
reduction - I should say that was chlorine - yes - chlorine right -
that's - the chemical test for hydrogen sulphide - something nitrate
- era -
Ex Have you actually seen the test being done?
018 Yes - yes - it - - it - it turns somethng - turns something that's
put on the paper black - I can see the colour's there - but I can't
remember - the er - what the - ? [unclear] - oh dear - [sighs] - [Ex
asks to pass on to question 5 - the teacher having asked for 4 to
be omitted].
5(a) 018 [Reads aloud] - number of electrons 6 [looking at table] - and
the mass number is 1 2 — so it'Id be ~ 2 um
Ex What1Id be two?018 - er - no - I was just trying to work out the electron structures
of these - .... er - two - it's got - er - that's E - .......um so
that'Id be 2 , 8 - number of electrons - 6 - mass number would be 1 2
- 14 - wait a minute see - ah - that's er - that’s 2 - 2 - 6 - no,
no it can't be - number - mass - oh dear - mass number is the number
of neutrons and - protons - number of electrons is 6 s s 9
9 so that's 2 - '11 be 2 , 8 , 1 - 9 oh no - 2, 8 - that would 2, 4
- number of electrons - number of electrons - it’ll be 2 on the inner
- A148 -
c
shell - and there'Id be 4 on the outer shell - no er - 2 - [mutter]
- aye - era - yes - that'Id be 2, 4 - that'Id be 2, 8 [writes this
under G etc] - um - what would that be - 4 - 28, 14 er that s 4
•s 14 that’s - 2 , 8 's 4 - 1 6 - 2, 8 - [Ex queries what he is doing]
.......yes - 'cause of what I know of - oxygen - that’s 0g - and the
number at the top is 16 - but the number of the electrons in the
valency shells is - 2 for the K shell - and 6 - 1, 2, 3, 4, 5, 6 -
for the L er - shell - so - from what I know of that - that'Id be
the - that's the electron structure - I'm working out the electron
structure - that's from oxygen - from what 1 know of oxygen - ’cause
- it gains - gains two electrons to make a stable - electron structure
- then it's 0 2 negative [018 appears to be subtracting the number
of electrons from the mass number and expressing the difference as an
electronic configuration in the various energy shells!] - so - 18, 36
_ .s er - oh dear - 10, 2, 8 - 's 18, so'11 be 2, 8, 8 that's stable -
- G and M stable - G and M've got stable electron structures ’cause
- they've got - 8 - electrons in the outer valency shell -which each
valency shell should contain - except the K shell which should only
contain 2 - so it’s - er - 4 that’s 2 - that’s 22 to that’s 2 - 2,
8 - so that’s 10 - no that’s too much - 2, 8, 8 - you’ve got 18 -
2, 8, 8 - that’s 4 - yeah, that’s 2, 8, 8, 4 and - wait a minute 19
- that’Id be 2, 8 , 8 , 5 - so they’ve the electron - electron
_ i-i oht - which atoms are isotopes of the structures - structures - rightsame element - which atoms - isotopes - got um - got the same number
of - protons - but they’ve got a different number of neutrons - same
number of protons but different number of - er - protons the electrons
1 =/ii-r>ne<5 of the same element - different - so that'll be - atoms are isotopes. - - that's got 18 - and that’s got - that'Idnumber of - that's got er - that s got
be M and Q -
Ex - now how did you get M and Q?
- A149 -
018 They've got the same number of prof - isotopes - have the same
number of protons - but they have a different number of neutrons -
and the mass number -
5(b) 018 [Reads aloud] - element - atoms are isotopes - which two - so
it can only be two - elements are in the same group of the periodic
table - 2, 8 - which two elements - rare - rare gases - are G and
M - which two elements are in the same group of the periodic table
- that’s - that’s ? [unclear] be G - G and - G and M ’cause they’ve got this - they got the - they've got - urn - stable electron structure
of - G's got 2, 8 and M ’s got 2, 8, 8 - that'ld be in the same - same
group 'cause they’re rare - got stable electron structure of rare
gases - and all the rare gases are in the same group of the periodic
table -
5(c) 018 [Reads aloud] - halogen - [agrees with Ex that it is a familiar
word] - halogen - which element is a halogen [in a whisper] -
[repeats] - er (I’ll just skip?) that one for a minute -
5(d) 018 [Reads aloud] - X reacts with L - [re-reads aloud slowly] -
something to do with the number of - er - number of electrons in the
outer valency shell - so er - it’ld be - L and X - L ’s got 2, 8, 6 -t Q — that
X h,» sot 2 , 8, 8 - 5 - that'. 2, 8 - that'. 6 th.fs
donates - you'.e got 10 to donate - 11. U « l - « °£ X *°d L ”“ h. "Vialance" numbers of electrons]electron configurations and trying
- erm - er -Ex You’re trying to see how they might swap electrons are you?
018 Yes - erm - that’s got - ? [unclear] 2, 8, 6 it s got
electrons to donate - 2 , 8, 8, 5 - 2, 8. 8, 5, - it’s got 3. 6, 9, oh
5(c)
6 .
6(a)
6(b)
5 - that's got - that can ? [unclear] that can lose - that can lose
them - those could gain them to form - that's - those - three - that's
got to gain 3, that's got to gain 3 - 1 2 [has 4 atoms of X] - and
that's losing - 12 electrons ? [unclear] [has 2 atoms of L] - and
that's staying on 2, 8, so that'll be 1 - L 2 positive - no - 2 - 2 L
positive - urn - 4 X negative - have to see if these ? [unclear]
you've got 10 - er no I think that's - 2 L positive, 4 X negative -
[whispers] - X reacts with L [was re-reading question] - yes it's
2 L negative - 2 L positive - 4 X negative - that's 3, 6, 9, 12
in that's losing 12 to gain electrons - stable electron structure
'n they've got stable electron structure — yeah-
018 [Re-reads aloud] - halogen - halogen - [agrees with Ex that he's
spent enough time on question 5].
018 [Starts reading aloud] - so it's dilute - dilute - [continues
reading - skips to a]•
018 [Reads aloud] - an excess of iron filings was added - ? [unclear]
- an excess was used because [writing as he speaks] the - a solution
of copper(II) sulphate - copper(II) sulphate - copper(ll) sulphate -
and iron filings - iron filings - Fe plus CuSO, - not too keen about
that - anyway - excess was used because - so as - as to saturate the
- the copper(II) sulphate solution thus using it up -
018 [Reads aloud] - before - to a solution of copper(II) sulphate
- a reddish-brown - reddish-brown precipitate was formed and the
mixture is filtered - iron filings - dilute - it could - it could
be - before crystalising the solution - substance - it must have
been iron - seeing that that was the - oh no - wait a minute - no
- A151 -
copper - I'm looking at the um - left hand instead of the right hand
- it'Id be - it'Id be copper - that was filtered I would think -
er reddish brown precipitate was formed - that'Id be - er iron
sulphate - well er iron(II) sulphate - before that was evaporated
and - yeah - that would be copper - copper -
6(c) 018 [Reads aloud] - oxidising agent - that's - that's - [has drawn
additional arrows on previously completed equation - see script] -
Ex What's this big arow for?
018 er - I've put a big arrow because the iron has gained oxygen in
the S04 - to become FeS04 - it's been oxidised -..... the thing which
has been reduced - which is from copper sulphate - to copper - that's
been reduced - so the iron acts as a reducing agent and the copper
sulphate - reacts as - er - the oxidising agent -..... [018 confirms
that the type of diagram he has constructed is the type he is used
to for redox reactions].
6(d)(i) 018 [Reads aloud] - the filtrate was evaporated taking all necessary
precautions - um - iron(II) - Fe - S04 - taking all necessary precautions - urm - [Ex cuts short as time is pressing and directs
to items 7 and 9].
7(a) 018 (Reads aloud] - [re-reads aloud] - don't really - um Room about
that in term. o( ehange. at the atomic level - 1 Unow «hat oxidation
is -
Ex Well - what is it?018 Well it’s er - oxidation is gain of oxygen oxidation from
another subject - another substance - at the atomic level -
oxidation - oh a loss of electrons is oxidation - [reads question
aloud] - yes it's loss - loss of electrons is oxidation [writes] -
- A152 -
7(b)(1)
7(b)(ii)
that means - you know - ..... you've got the ions present but - whenI
you — take the electrons — so when you add the electrons to the other
substance - It's losing them -.....
018 [Reads aloud] - oxidation - loss of electrons is oxidation - in
each - underline the substance which is being oxidised - ? [unclear]
- gain - that's gaining.
Ex Sorry - what's gained?
018 Gain of electrons is reduction - and that would be - Fe - under
line the substance which is being oxidised - that'Id be the Fe - the
Fe 2 positive -
Ex Why's that being oxidised?3+018 Well the - that's er - the Fe on the other side is - erm -
that's got 3 positive ions - and it's - er - it's losing - its los'
- oh dear er yes - it's losing an electron - whereas that's becoming
- erm - that's sort of er gaining that electron from there - so
that'Id be - Fe 2 positive - [trails off] -
018 Cu - ? [unclear] underline the substance so there must be only
one - couldn't be - Br2 - that gain - that is gaining electrons -
that'Id be the - that'Id be the - bromine - oh no - er - it'd been
- yes that'd been oxidised - yeah that'd be the bromine - because
that's gaining - that's going from 2 Br - to 2 Br negative - so that
started off from naught — it's now become - well that was negative
but is now become - 2 - 2 electrons that's become 2 negative so that's
been oxidised — gained — no wait a minute would that be gained? —
gain of electrons is reduction — um — I'm not — not too sure about
that one [however leaves it].
- A153 -
A*
7(c)(i) 018 [Reads slowly aloud] - name the industrial processes used -
..... catalytic oxidation - reduction of nitrogen to ammonia -
probably read my notes on this - but we haven't er - we haven't -
we've covered er some industrial processes - i.e. catalytic cracking
and er - oh - you know - different industrial processes but I'm not
too sure about - er - the oxidation and the reduction of those two
- I'm not too good on them - playing about with the iron bits
Ex No - nitrogen in the air being converted to ammonia - it's a very
important industrial process - for making fertilisers and so on
018 Nitrogen -
Ex Nitrogen to ammonia.
018 er - ..... [018 goes on to item 9 after discussion with Ex].
9(a) 018 [Reads aloud] - hydrocarbon series - it'll be - is it an alkane
Ex Well if it was propane it would be an alkane.....
018 - oh sorry - propene - I read that wrong [in fact he read it aloud
correctly] - I'm sorry - yes - propene - that’ll be an alkene - ...
9(b) 018 [Reads aloud] - propene - 's got - C - draw the structural formula
of propene - that's a C - C - that's a C - that’s 3 - oh dear - urn
- CH - er - how many electrons has carbon got - er - C - CH - I think
it's CH2 so it's got to be - it’s got to be 2 that's H
Ex Now what's the CH^ come from?
018 Well er -
Ex You just divided by 3 did you?
018 - just divided by 3 because - er - can’t remember how many -
electrons there are in - carbon in the outer valency shell - er if
it's - it's C - so it'Id be - that'Id be - C - CH - CH - urn - CH is 4
- so that'Id be - that'Id be er - that'Id be 1 , 2, 3, 4, 5, 6 -
- A154 -
those'Id be hydrogens - hydrogens - sorry about the diagram - I can
draw it on there again [Ex assures 018 that this is not necessary]
- um - that's a carbon that's a carbon that's a hydrogen [is labelling
atoms in electron diagram he has been drawing while speaking] - cross
- hydrogen - well this is how - we usually do - the er - models.
Ex Yes - that's quite clear -
018 And then there'Id be - that'Id be - er - oh dear - how many's
that -1 , 2, 3, 4, 5, 6 -
Ex You're putting in electrons there are you?
018 Yes - I'm putting in electrons - no that's - 2 , 3 - 2 - 3 , 4
-there's 2, 4, 6, 8 - I'm trying to make the -
Ex You're trying to give them all 8.
018 Yes - stable electron structures - that's the carbon - and that'll
be er - that'll be - be 2, 4, 6, 8 - so that's two ? [unclear] -
there's a sharing - you've got - you've got double bond - they've got
er double bonds between - er the - Cl^s - you've got 3 CHj molecules -
who've got to have a stable electron structure of 8 for each of them -
[Tape runs out].
TAPE ENDS
- A155 -
1(a)(1)
1(a)(ii)
1(b)(1)
UbXii)
PUPIL 019 - TRANSCRIBED PROTOCOL (TEST 03)
019 [Reads aloud] - well this will be oxygen because the - hydroxyl
ion is - given off more easily than the - sulphuric - sulphate ion
won't be attracted - to the anode [019 insists that he obtained the
answer in the way stated] -
019 [Reads aloud] - 'cause it'll be hydrogen - 'cause it's the only
positive ion - [writes] .
019 [Reads aloud] - because - for the same currents - for every
hydrogen - two hydrogen ions that are attracted to the - cathode -
there will be one molecule of hydrogen evolved - but for every 4 -
hydroxyl ions attracted to the anode there'll only be one oxygen
molecule evolved - and because — er — equal — numbers of moles evolved
- and because - er — equal - numbers of moles of the gases occupy
the same volumes - at the same temperature and pressure then you have
a 1:2 ratio. [Ex confirms that he would like 019 to write his answer
on the paper and asks for more information about how the ideas were
generated — eg the 4 OH etc]. Well, I happen to know that when
hydroxyl ions are attracted to the anode then you get water formed
and one atom of oxygen for every two of hydroxyl attracted -
remembering it from my notebook - yes - [writes - omitting reference
to Avogardro's Law].
019 [Reads aloud] - I don't know - ? [unclear] - well it - oh I don't
know -
Ex Any -
019 The only thing I know of that effects electrolysis is polarisation
but - I don't really know anything about that except that - it stops
electrolysis working.
- A156 -
Ex You - couldn't speculate about any possible reasons?
019 - ? [unclear] - um -
Ex OK - never mind -
1(c)(1) 019 [Reads aloud] - um - Increase the concentration you'Id have more
- hydrogen ions - but - if the current's constant - then - it wouldn't
affect the - volume of hydrogen ? [unclear] - [Ex Asks 019 what he
is pondering] - well - the current - at the anode - the cathode -
it's er - it's transferred to the hydrogen ions and the hydrogen ions
are evolved as hydrogen molecules - but - if there's the same amount
of current then you're not going to be able to - transfer - more of
it to hydrogen ions even though there are more hydrogen ions - and
so there wouldn't be - the volume of hydrogen evolved would stay the
same. [Ex congratulates and encourages].
1(c)(ii) 019 [Reads aloud] - well I don't think again that this would make
any difference - because - it just wouldn't affect the number of
hydrogen ions required to - um - well neutralise the current coming
from the cathode [writes].
1(d) 019 [Reads aloud] - well I can remember this I think, from the
textbook - it’s something I've learnt - through a copper wire - the
conduction of electricity is by move' - well by electrons because
it's metal - and that's the method of conduction of electricity
through metals - but in sulphuric acid there are ions present and
the - ions are attracted to the - cathode or - anode or cathode
and they either gain or lose an electron - from the cathode or anode
- and become atoms or molecules - and so - it's different in that
respect - [writes]. [Ex encourages].
- A157 -
2(a) 019 [Reads aloud] - well er - I remember this - the formula for the
ammonium part of a compound is NH^ - but it's got a valency - and
carbonate - part has got a valency of 2 - the radical - and so I
have to have 2 ammonium - to - er - make it balanced - and so I've
written down NH^ brackets twice - CO
2(b)(i) 019 [Reads aloud] - well this is something I've remembered - you can
- you - it's cobalt chloride paper I think and under normal conditions
- it's blue and it turns pink - I always get that the wrong way round
so I don't know - and then for further proof you could obtain a sample
of the water and - boil it and take the boiling point - and if it
was 100°C it would be pure water - so I'm writing that down now -
using cobalt chloride paper and observing the colour change from blue
to pink - further testing by boiling and measuring the boiling point
- to be 100°C -
019 [Reads aloud] - urn - I'm sorry - I haven't got - we haven't really
done this yet -
Ex Well - it says at the front of the book you might be asked to do
things you haven't done before -
019 Yes -
Ex It’s just to see if you can apply ideas you should be familiar
with even if you haven't met urea before - so have a go please.
019 Covalent compound - urn - um -
Ex Now a long pause - what is it you're wondering about.
019 I don’t really know where to start —
Ex Well - what do you think a structural formula is - what sort of
thing is it asking for?
019 A diagram -
Ex Yes - with what?
I 2(b)(ii)
- A158 -
019 The - um - letters to represent where the atoms are placed -
Ex Yes -
019 Well - I'll put the - CO - a covalent compound so - I'll have
to draw lines to represent the covalent bonds - um - it's - twice
I think they'Id be a double bond between the carbon and oxygen in the
CO and then single bonds coming off to the - N H - um - parts - and
so it's - an N joined to 2 hydrogens - [drawing] - ? [unclear] fill
in the bonds - N joined to 2 hydrogens by covalent bonds - [Ex
encourages].
3(a) 019 [Reads aloud] - um - this is something I can remember - it's
oxidation of hydrochloric acid I think - and chlorine's evolved.
Ex Yes — do you remember it from -.....
019 From my notebook - chemical test - for chloride - um - chemical
test for chlorine - you could use litmus and it would be slightly
acidic - [Ex asks how he is approaching this problem..... I'm thinking
of - I'm trying - I'm running through a list of tests - so - 's -
er - it has some reaction with an alkali but I can't think how you
could use that with sodium hydroxide - um - could you use that - to
test for it - and there's some others - there's potassium dichromate
solution - would it be - or potassium permanganate [under his breath]
- test for chlorine - no - I can't think of one - could react it with
sodium hydroxide and then you'Id get - it depends what temperature
it is - and concentration - oh I know what you could do - you could
react it with hot concentrated sodium hydroxide and then you would
get some sodium chlorate formed - I can't remember what else - and
then you could crystalise this out - no I don t know um
and then you could er - spray the sodium chlorate on weeds and it
would [laughter from 019 and Ex]..... well I can't think of anything
else.
Ex Why not skip it for the moment?.....
- A159 -
3(b) 019 [Reads aloud] - iron(II) sulphide and dilute hydrochloric acid
- sulphide ? [unclear] confusing - erm - ..... er -there's a -
sometimes you get a - sulphur precipitate - iron(II) sulphide and
hydrochloric acid - what gases could there be - hydrogen and chlorine
- and - that's it - oh hydrogen sulphide - hydrogen sulphide - iron
- I'Id say it was hydrogen sulphide - ..... because it seems the most
likely out of hydrogen and chlorine and hydrogen sulphide [writes] -
name of gas - hydrogen sulphide - chemical test for hydrogen sulphide
well I can remember this — it's um — the general test — if you —
hydrogen sulphide in - with water - if you react it with potassium
dichromate you get a colour change - orange to - orange to green I
think - so I'll write that down - [does so] - hydrogen sulphide with
water reacted with potassium dichromate solution colour change from
orange to green.
3(c) 019 [Reads aloud] - ammonium salt plus alkali gives ammonia - I'm
not sure if I'm remembering that correctly but - ammonium chloride,
calcium hydroxide [under his breath] - we've done this and I'm trying
to remember the work in my book - ? [unclear] can I have a piece of
rough paper - ..... I'm writing down an equation now to see if I can
work out the gas [writes NH^Cl + CaiOH^"^ NH3 + CaCl] calcium
hydroxide - yes it is ammonia - you get NH3 plus an extra - HC1
left over from that - ? [unclear] - oxide doesn't react with - I don't
know - gas - hydroxide - - I'm thinking of calcium chloride and water
just by - separating out what the components of the various compounds
- and trying to rearrange them into different compounds - calc'
calcium chloride - so I've decided it's ammonia gas that's evolved
[writes] - chemical test for ammonia - now I can remember there s a
solution called Nestler's solution - and if you dip that in some
dip a filter paper - damp filter paper - and - in Nestler's solution
and — then you put it in some ammonia — if it *s ammonia then there's
a colour change from green to brown [Ex establishes he recalls this
from doing it and also from having it written down] - [writes] -
Nestler's solution - colour change from green to brown.
3(c) 019 [Reads aloud] - urn - chlorine's an oxidising agent I think - I
can remember that [writes] from er - when we're written down lists
of oxidising and reducing agents [starts reading 4 - Ex interrupts
to check on a previous answer].....
Ex [Referring to 2(b)(ii)] - ..... were you checking that the valencies
were right or anything or were you.....
019 Yes - I had in my mind that nitrogen has a valency of 3, carbon a
valency of 4 and hydrogen a valency of 1 and I was trying to balance
them all -....
4(a) 019 [Reads aloud] - I think I can just define this using the - phrase
itself - oh there's another thing - enthalpy change - we've just been
going over that - so I should say it's the enthalpy change when -
enthalpy change when - 1 mole of acid neutralises 1 mole of alkali
- that's the best I can do I think [writes] - ..... enthalpy change
when 1 mole of acid completely neutralises 1 mole of alkali -
4(b) 019 [Reads aloud] - to find approximate heat of neutralisation -
you're trying to find a change of temperature - so that you can use
it in your calculation - and I think that you would use plastic
because - it wouldn't affect the results - it wouldn't make them less
accurate beause it doesn't absorb very much heat - it wouldn't er
- give you a loss of heat - and also because it's a - because it
doesn't absorb much heat - I'm writing that down [writes] - because
it does not absorb much heat energy -
- A161
Ex Have you actually done an experiemnt like this?
019 er - yes we have - yes - we used some polystyrene containers -
Ex But — you weren't remembering a reason for using it — you were
sort of working out what must be a sensible -
019 Yes - I was working out a sensible definition -
4(c) 019 [Reads aloud] - we've done the definition and - well - 1M nitric
acid - it's a — strong acid which means it's - a very large percentage
is ionised - ? [unclear] - 1M potassium hydroxide - a very strong
alkali - so it's very largely ionised - and so there won't be energy
- used up in separating - ionising the - er - molecules if it's a
weak acid - or alkali - in the first experiment there were also - I
think - strong acids and alkalis - and the overall explanation is
because - you're forming one mole of water - for - the same number
of moles of reaction - reactants - and because you're forming one
mole of water - from a hydroxide ion and a hydrogen ion - or a
hydrated hydrogen ion - then - in each case - then the heat energy
evolved is - exactly the same - so I'm writing that down [writes]
- because they are both strong acids and alkalis and the overall
reaction is the same in that one mole of water is formed from one
hydrogen hydrated ion - hydrated hydrogen ion - and one hydroxide
ion.
Ex Just before you go on - that is an explanation you're familiar
with - you've come across that explanation before?
019 Yes we've - we've been - we've done the reaction and we were told
the explanation - .....
4(d) 019 [Reads aloud] - what would happen to the measured rise in
temperature - well this is also a strong acid so it would have the
same result but - in the second case - 1M ethanoic acid - CH^COOH -
- A162
this is a weak acid and so — some of the energy would be used up in
ionising — the acid — (simultaneous reaction ?) — and so you'ld have
less energy evolved and the temperature rise would be smaller - and
so I'm writing that down — what would happen to the measured rise
in temperature - [writing] I'ld say that it would stay the same -
it would stay the same - it would fall -
Ex Just let me stop you again before you go on - the 1M sulphuric
acid - formula l^SO^ - so - um comparing it with HC1 - you've got 2
hydrogen ions per mole - so that a molar solution is going to produce
twice as much — would that make you want to reconsider your answer?
0i9 I think so, yes. [re-reads d(i) aloud] - let's see - heat of
neutralisation - ? [unclear] 1M acid neutralises 1M alkali - .....
[Ex interrupts as 019 obviously is in no hurry to change answer and
discusses briefly before moving him on].
5(a) 019 [Reads aloud] - number of electrons - mass number - mass number
is the number of protons and the number of neutrons - and the number
of elect' - yes - the number of electrons is also the number of
protons - which atoms are isotopes of the same element - then they're
going to have the same number of protons - or electrons - but
differing numbers of - neutrons - so it's going to be M and Q -
they've got the same number of electrons but differing mass numbers
- and therefore they're isotopes - oh isotopes are atoms - with the
same number er - the same atomic number but differing mass numbers
- so M and Q.
5(b) 019 [Reads aloud] - same groups - of the periodic table - group -
groups extend downwards - so they're going to have the same number -
of electrons in the outer shell - that means they're going to have
the same number of electrons in the outer shell - and I'm going to
- A163 -
have to work out I think this shell - the electron configurations
- so that's going to be 2 and 4 - that's going to be 2 and 7, 2, 8
- and 4 uh — that's E and J I think - I'm - E and J I've found have
the same - number of electrons in the outer shell so I'll just check
that - 2, 4 see - 2, 8 - 2 and 4 yes - so that's E and J.
5(c) 019 [Reads aloud] - halogen - oh - group - seven - it's gong to have
7 electrons - in the outer shell - which is G - 2 and 7 - using the
electron configurations.
Ex How did you know that halogens were group VII?
019 I remembered that -
Ex Just remembered - you weren't sort of visualising the table and
counting or?
019 Oh - yes I did actually visualise the table - I didn't count them
- I just - .....
5(d) 019 [Reads aloud] - X - where's X - these - 19 I've got to work out
the number of electrons in the outer shell - then this'll give me
an indication of the valency - I can work out the valency from that
- so X is 2, and 8 is 10 - and 8 - is 18 and 1 - so it's got a valency
of 1 - L - and 8 is 10 and 6 - erm - so it's going to be in group
VI - it's got a valency of 2 'cause it's 8 minus 6 - so t's going to
be - X2L [writes] - so that everywhere's balanced.
6(a) 019 [Reads aloud] - I'll have to read the question again - [re-reads
first two sentences] - looks like a displacement reaction OK -
[continues reading] OK a reddish-brown precipitate was formed and
the mixture was filtered - oh the reddish-brown precipitate would
have been the copper - the mixture was filtered to remove the copper
because the copper was replaced by the iron - the iron's higher up
- A164 -
in the electrochemical - series - the filtrate was evaporated - what's
the filtrate - the filtrate is - er one you get out - the iron(II)
sulphate solution is evaporated, taking all necessary precautions,
until a saturated solution was formed - the solution was then cooled
and the crystals were filtered off and dried. Why is an excess of
iron used - well the iron's displacing the copper - from the solution
- so if you use an excess of iron filings - then you’re going to make
sure that all the copper's displaced and you haven't got any copper
sulphate solution left - so 'll write that down - to ensure complete
displacement of the copper ions from solution..... [019 agrees that
this explanation is probably transferred from a case he has met
before].
6(b) 019 [Reads aloud] - filtered off - a reddish-brown precipitate was
formed - well you're filtering off the reddish-brown precipitate -
elemental copper [writes] elemental copper.
6(c) 019 [Reads aloud] - now oxidation - an increase - an increase in the
oxidation state - I prefer to do it using oxidation states - which
of the substances used acted as an oxidising agent - crystals of
iron(II) sulphate were prepared as follows - copper(II) sulphate in
water - ah - now the copper was - it used - it did have a valency
of 2 - did have an oxidaton state of + 2 in the copper sulphate
solution, but it's - precipitated out and therefore it has - an
element in its - its elemental state has an oxidation state of 0 -
and so it's - reduced from 2 to 0 and therefore - it has in fact been
reduced - acted as an oxidising agent - ah - now you had iron - metal
iron that went from 0 to + 2 oxidation state - but oh crumbs - if
something acts as an oxidising agent - then it itself is - reduced
- and so I - I think I will say copper [writes] [under his breath]
- A165 -
- it can't be - that doesn't seem right somehow - to a solution
of copper(II) sulphate in water a reddish-brown precipitate was formed
the mixture was filtered — well the iron is the substance that's
oxidised — and I think it would have — copper — copper sulphate —
no, I'll say copper.
6(d)(i) 019 [Reads aloud] - [reading] "the filtrate was evaporated taking
all necessary precautions until a saturated solution was formed” —
well> I know the iron in iron(II) compounds tends to oxidise to
iron(III) compounds — iron (II) sulphate - a special precaution had
to be taken during evaporation - well the precaution would be to
ensure that - it remained as iron(II) sulphate - but I'm not sure
how you would do that - [reading again] iron(II) sulphate - a special
precaution had to be taken during evaporation of the filtrate - to
obtain a reasonably pure product - what do you think this precaution
might be - well you wouldn't heat it - because that would - er -
increase the rate of oxidation - of the iron(II) - a solution was
formed - I think they're after an explanation of how - to - take this
precaution - ? [unclear] - but you want to do it as quickly as
possible really - 'cause the longer you leave it the more it will
oxidise - (solution?) -
Ex If it's going to oxidise, what oxidising agent are you - having
in mind here?
019 er - the atmosphere I suppose - if it's exposed - because I know
that iron(II) hydroxide tends to - in solution - it's oxidised to
iron(III) on the surface in the test tube - and so - on exposure to
the atmosphere or - what do you think this precaution might be - it
would be the urn - er - no, I don't know -
6(d)(ii) 019 [Reads aloud] how might this pre' - oh [laughs] - how might this
precaution be taken - well - for the first one then I'm going to
write down that - you ensure that the [writing] - the iron(II) is
not oxidised to iron(III) — how that precaution might be taken — I've
just been consdering that - I don't know -
6(e) 019 [Reads aloud] - mass of crystals obtained was much less - than
that calculated from the balanced equation for the reaction — ah -
[Ex explains that there is no link with the last part-question] -
019 Oh - I see - [re-reads item aloud] - [reads aloud last two
sentences of stem] - mass of crystals obtained - well [doubtfully]
I suppose you could have lost some when you were drying it - filtered
off and dried - er - I don't really know this either - [Ex suggests
moving on owing to shortage of time].
7(a) 019 [Reads aloud] - in terms of changes at the atomic level — what's
it after - atoms - electrons - changes at the atomic level - well
I - I'm trying to remember my definitions of oxidation - it's an
increase in the oxidation state but I don't - - might be able to use
that - it's an - loss of electrons - [under his breath] loss of
electrons - an increase in the - non-metallic part - yes - I think
- what they're after here is a loss of electrons because - that's
- really the only one - that ? [unclear] - er concerns the atomic
level - oxidation is [writing] the loss of electrons - just make sure
it is the loss of electrons and not the gain of electrons - ?
[unclear] - here's something ole - that's O L E - and it's a loss
of electrons.
7(b)(1) 019 [Reads aloud including equation] - urn - well - er oxidation is
the - an increase in the oxidation state - and the iron is reduced
- A167 -
7(b)(ii)
7(c)(1)
7(c)(ii)
- and the hydrogen Is oxidised - because it goes from an oxidation
state of - I think it's naught - it's in a bracket - to plus 1 - being
oxidised - I'll under - line it - I'll underline the H in a bracket
[does so].
I I
019 [Reads equation aloud] [interrupting self at Cu ] copper is
oxidised because it goes from an oxidation state of - naught to plus
two - so I'll underline the copper -
019 [Reads aloud] - ah I can remember this it's the er - contact
process - for making - it's sulphur trioxide, sulphur(VI) oxide so
you use that for making sulphuric acid - [019 agrees with Ex that
he translated the names of the oxides to SC>2 and SO^] - so I'll write
down contact process [does so].
019 [Reads aloud] - reducation of nitrogen to ammonia - I don't think
I know this - what - process do I know involving nitrogen and ammonia
- there's the Haber process - er - Haber process - nitrogen and
hydrogen - yes I'm going to write down the Harber process there [does
so] .
[Owing to a late start and the next pupil waiting the tape was
concluded].
TAPE ENDS
- A168
PUPIL 020 - TRANSCRIBED PROTOCOL (TEST 03)
l(a)(i)/(ii) 020 [Reads aloud] - well - the two - anions present will be the
sulphate and the hydroxide - 'cause hydroxides - in the electro
chemical series it's more likely to be - urn -evolved unless it's very
concentrated it'll be - oxygen - [in reply to Ex 020 confirms that
she actually worked out the answer as stated] - um well - the other
gas'll be hydrogen - I just know that - I'm writing that down.
l(b)(i) 020 [Reads aloud] - well - water’s H20 - it's going to be two - moles
of hydrogen atoms to two - moles of oxygen atoms - I'll write that
down [does so] -
JÜ2L..... you've talked about electrolysis of water there - when you
first read the question - dilute sulphuric acid is electrolysed -
did you say to yourself this is electrolysis of water' or -
020 No - not at all.
Ex - so where has this idea about water being electrolysed come from?
020 Wel1 “ as it's the hydroxonium and the - hydrogen that's been
electrolysed - ? [unclear] - [Ex goes on to establish that 020
recognised that Avogadro's law was assumed, though she was (i) unaware
of assuming it and (ii) did not, even after recognising it, regard
it as necessary to the answer].....
1 (b)(ü ) Q20 [Reads aloud] - er - no idea really - may be - some sulphate is
electrolysed and not all oxygen - er - all the gas isn't given off
at the electrodes - I don't know - er the oxygen has to um - combine
- so it might take longer for it to become - actually oxygen I suppose
- so I'll put that down [does so].
1(c>(i) 020 [Reads aloud] - well - if you increase the concentration - of
something - it often means that - the electrochemical series is
- A169 -
fit
not always followed — that could mean that um — that um — oxygen is
no longer electrolysed and that it's um - sulphur - perhaps - 's all
I can think of [writes].
l(c)(ii) 020 [Reads aloud] — well this would also — increase the concentration
if it got hot enough - some of the water - I don't know - I expect
the same thing - [writes].
1(d) 020 [Reads aloud] - through a copper wire it's um - tah - ? [unclear]
by the electrons in the copper which — bump into each other and pass
the electricity along - where in the dilute sulphuric acid it's - the
presence of ions which move to the anode and cathode - [Ex establishes
that this is recalled from notes - 020 writes answer]. [On going
back to discuss the answers 020 agreed that she tackled (b)(ii)
and (c) by "guessing" and then deciding which guess seemed most
likely].
Ex ..... have you any idea how you generated these guesses? [However,
aside from a reference to recall nothing further emerged].
2(a) 020 [Reads aloud] - well - the ammonium radical is NH^ and that has a
valency of 1 - and the carbonate is CO2 and that has a valency of - 2.
Ex How did you get that 2? - there was a distinct pause.....
020 Well I was just looking at the table of valencies and checking
- and thinking of calcium carbonate - which I think is CaCO^ and I
know calcium is 2 so - that means there'll be 2 of the ammoniums for
the carbonate - I'll put it down - CO^ - I said CO 2 um -
2(b)(1) 020 [Reads aloud] - well that's just memory - um - er - cobalt
chloride paper - [writing as she speaks] - and to verify absolutely
check the boiling point was 100°C -
- A170 -
2(b)(ii) 020 [Reads aloud] - ah - well - start with the ammonia -
Ex Well presumably as you read that you - had some idea what was
wanted as a structural formula?
020 Well - I assume it's drawing it - drawing it with the covalent
bonds in -
Ex Yes -
020 [drawing] - nitrogen has got - er - 5 - 5 electrons in the
outermost shell - yes that's right 'cause it's NH^ - and hydrogen's
got 1 - try drawing two bonds there - carbon monoxide - well carbon's
4 - and - oxygen' s 6 - urn -
Ex How what are you drawing?
020 Urn - trying to work out the - the CO bit - well there's 1 carbon
- ? [unclear] - bond there -
Ex So you're drawing electrons and things - could you tell me what
it is you be trying to do?
020 Well, I'm - drawing how many electrons there are in the outermost
shell - and they're covalent so they each donate one to form a
covalent bond - so I'm trying to work out - failing - what er - trying
to - work out the bonding [Ex establishes that 020 does not think
electron diagrams are required] - ..... well hydrogens are satisfied
- got one there -well the oxygen needs another one - so that could
go there - and, the carbon needs - oh dear, this isn't right - oh
it's perhaps got a double bond with the oxygen - that could be
possible - what could that mean - carbon still needs 2 more - that's
the carbon - cross that out - let each nitrogen - ? [unclear] to 2
hydrogens - like that - and the 2 - the - NH twice er - so I've
drawn 2 of those and 1 of the carbon monoxide - that was a double
bond - and one carbon to each of the nitrogens - well - uh - ?
[unclear] - hydrogens have got - check it through - the hydrogens
have all got 2 now - that means their electron shells are full - the
nitrogens - 3 - yes - it looks right -
Ex You didn't check the carbon then?
020 No “ well I did actually in my head — um ? [unclear] —
3(a) 020 [Reads aloud] - well that is the reaction where you show that
— hydrochloric acid is a — no — manganese dioxide is - ah — either
an oxidising agent or a reducing agent - I know it's chlorine anyway
- I know that - chemical test - oh dear - bleaching properties - or
acidic properties - one or the other - ? [unclear] be - [agrees that
she is thinking through properties of chlorine] - um - normally I
would have learnt these off by heart -..... um oh dear - well it'll
~ if you add red litmus paper — damp red litmus paper [writes] it
would go - no blue - blue litmus paper - litmus paper - damp litmus
paper - it would go red and then white - it would show acidic and
then - bleach that's right [agrees that she has now recognised this
as a familiar test] .
3(b) 020 [Reads aloud] - oh - well - iron(II) sulphide - well - what could
you get - um - I suppose you could get sulphur dioxide - chlorine,
hydrogen - iron sulphide [whispers] - ..... my notes - I'm trying to
remember - ..... well iron(Il) sulphide - what do I know about iron(II)
sulphide - ? [unclear] - ah! - it's hydrogen sulphide production.
Ex When did that suddenly come from?
020 - I don't know - I just - I can see the page actually - where it
says - I was thinking anything I knew of iron sulphide and I saw iron
sulphide in hydrogen sulphide production that was all [writes] -
hydrogen sulphide chemical test - again think about the properties -
hydrogen sulphide reacts with sulphur dioxide - to give sulphur and
- A172
water - does that count as a test - well it's acidic - don't - it
smells but that's not a chemical test - um - urn - I think I'll put
it reacts with sulphur - dioxide [writes] - .....
3(c) 020 [Reads aloud] [puzzled] - um - now what can I get - chlorine -
hydrogen and oxygen — or ammonia — oh yes it's ammonia [writes].
Ex Again you settled very positively on ammonia.
020 Yes, because I thought and then I - remembered - chemical test
for ammonia - ah - Nestler's solution [writes].
Ex Do you remember that from a page in your notebook or from seeing
the test or ? -
020 - list of chemical tests - now does it go from brown to orange
or orange to brown?
Ex Now a lot of these things in chemistry that are either one way
round or the other way round - how do you get it the right way round?
020 Well at the moment I'm trying to think of the bottle - what colour
it is - um - for instance the cobalt chloride earlier on - I was
trying to think - what colour the paper was.
Ex You were trying to visualise it?
020 Yes - I think it's orange to brown [writes] - is that ammonia
- yes it is - no it isn't - yes it is - um - well it reacts with
hydrogen chloride as well - shall I put that instead - I'm sure of
that - no I don't think it is Nestler's solution - urm - with stopper
[writing] of hydrochloric acid - produces white smoke - of ammonium
chloride -
3(d) 020 [Reads aloud] - chlorine, hydrogen sulphide or ammonia - oh dear
- think - oxidisng agents are - to the right of the periodic table
- and that's chlorine isn't it - and it's fairly near the top - best
oxidising agents are at the - top - right hand side - I don't know
- hydrogen sulphide - I think that's reducing so I don't think ?
[unclear] -
Ex Why do you think it's reducing?
020 Memory again - um - ammonia - ammonia - think about ammonia -
what's ammonia do - well it reacts with er - oxygen - that doesn't
show it s an oxidising agent does it — it reacts with oxygen — to
produce nitrogen and water - no it doesn't - ? [unclear] - yes it
does - let's write it down and see - what kind of reaction it is -
oxygen - well - in oxygen -
Ex So you've written an equation there?
020 Yes, I've written an equation down so I can work out what's
oxidising and what's reducing - oxygen in its elemental form is 0
and with hydrogen it's minus 2 -..... that's a decrease in oxidation
state so that's been - reduced - nitrogen well nitrogen is - plus 3
three and 0 there so that has been oxidised - so if the ammonia's
been oxidised it can't be an oxidising agent - well that's one example
- it doesn't prove it - well as chlorine's at the right of the
periodic table I think I'll put that down - [writes] - right.
[Ex asks to check answer to 2(b)(i) before going on] -
020 -I didn't actually put the colours down - ..... 'cause I couldn't
remember which was which - .....
020 [Reads aloud] [interpolates that's thermochemistry after "heat
of neutralisation"] - ..... "arrangements were made” - yes I recognise
this - what is meant by heat of neutralisation - it's the enthalpy
change [writing] - involved when dilute acid reacts with dilute alkali
to produce one mole of water.
Ex Well that sounds as if it's coming straight out of your notebook -
020 Yes - .....
- A174
4(b) 020 [Reads aloud] - Insulating - I suppose -
Ex You say I suppose - that's initially a guess that you're going
to consider or..... ?
020 Yes -
Ex Or is it something that you've actually talked about - you said
you recognised the experiment.
020 Yes - well -.... I don't think we did [talk about it] -......
insulating - well, what else can you use - metal - well it'll react
with metal perhaps - glass - why don't you use glass - urn -I think
I 11 settle for insulating — to prevent heat loss and so make it more
accurate [writes].
4(c) 020 [Reads aloud] - this is because [writes immediately] the reaction
is essentially the same - [agrees it is straight from the notebook
as they have just done it] - is essentially the same as in both cases
- the hydrogen in the acid is reacting with the - OH radicals - OH
radical in the alkali - to produce water.
4(d) 020 [Reads aloud] - now - it would be double - wouldn't it - because
the sulphuric - something to do with - um - well double the amount
of hydrogen - yes - it doesn't ask for an explanation - it just asks
what happens - would it be double - it would be more wouldn't it -
ah - I'll work it out - write two equations - [writes] - the hydro
chloric acid and the sodium hydroxide and the sulphuric acid and
the sodium hydroxide -..... - um - + NaOH gives Na two SO^ +
H^O - balance it we've got 2 hydrogens there - and 2 hydrogens there -
we need 2 sodiums so put a 2 in front of the NaOH - that means we
need 2 oxygens and 2 more hydrogens so we put 2 in front of the ^ 0 -
now that's balanced - so - 1 mole of the acid produced 2 moles of
the water - but we need 2 of the alkali - um - whereas in the other
- A175 -
case it s 1 mole reacts with 1 mole to give 1 mole — agh — [Ex asks
to think aloud] — one mole — ? [unclear] — yes — so does that mean
- the temperature rise - because you need double the alkali - now
in the experiment that we did - we used the same amounts but — yes
we used the same amounts - when we did the different acids but we
got different heat of reaction - oh dear - I think I'll put -
[writing] the temperature would be higher - ah - ethanoic acid well
- that is a less reactive acid so the temperature is lower - [writes]
[020 admits she simply knew the answer and did not "work it out"].I
5. 020 [Reads aloud] - right - number of electrons right - same as the
number of protons — 's to do with — er atomic structure — mass number
is the total number of protons and neutrons in the nucleus - [finishes
reading part (a)] - isotopes - have the same number neutrons but
different numbers of protons - so they'll have the same number of
electrons - but - different mass - number - did I say neutrons - same
number of neutrons and different number of protons - I meant the other
way round if I did - which atom are isotopes of the same element -
I'll look for the same number of electrons - M and Q -just check that
their mass numbers are different - yeah -
5(b) 020 [Reads aloud] - the same group - same group - that is - downwards
- downwards they'll have the same number of electrons in the outermost
shell - which two elements - so it can't be M and Q - it can't be the
same - atoms - can it - so - I'd better work out the electron
structure - yes the electron structure - so - L, 2, no K2, K2 so
that's be A, E'll be A - I'm writing it over the top - G will be - 7
- so those can't be the same then - 1A - er that'll be A so it's E
and J - better go right through and check - that'll be 6, that'll be 8
and 8 - and that'll be 1 - yes - E and J [writes].
- A176 -
5(c) 020 [Reads aloud] - halogens have 7 electrons In the outermost shell
- so that 'll be G -
Ex How do you know halogen has 7?
020 - because It's a group VII - ..... just remember it yes -
5(d) 020 [Reads aloud] - oh - what does It mean by that - derive a formula
- oh I see yes - er X - well - first of all write XL down - got to
work out the valancy of X and L - and therefore - yes - which is
electron structure again - 2, 8 - so it'll be 10 - and 8 again - 1 -
so that is 1 - X is valency of 1 - L - valency of 8 minus 6 which is
2 - 6 electrons in the outermost shell - 1, 2 - so there'll be 2 of X
X2L - write that in - [020 confirms that was initially written first
because it was named first in the question and that this was not
reconsidered at any stage].
6(a) 020 [Starts to read aloud] - "a reddish-brown precipitate" - ?
[unclear] - that must be the sulphate - [continues reading] - 'cause
otherwise there'll be er - some - some er - copper(II) - copper(II)
sul' - oh dear - write down the equation first then I can work it
ou*: “..... 0 plus CuSO^ - this is a displacement reaction
- no it isn't - ? [noise] - rubbish - scrub out that - Fe plus CuSO
gives - I presume that's .7H20 - FeSO^ point 7 H20 plus - and that'll
be copper - it is a displacement reaction - em - 7H20 to balance
- one Fe - SO^ - SO^- Cu - Cu - yes it's balanced [re-reads (a)
aloud - oh dear - oh dear - to make sure - all the copper sulphate
[writing] - yes to make sure all the copper sulphate was reacted so
it wouldn't go through when you filtered yes - [finishes writing]
- I worked that out by - the solubilties of the - working out that
copper sulphate was soluble - so therefore it must go through the
filter paper - it would be - it wouldn't be pure if um - when you
evaporated [020 agrees she is applying this from a similar
example] -
6(b) 020 [Reads aloud] - well that'll be copper [writing].
6(c) 020 [Reads aloud] - well work from the - formula - Fe in the elemental
state has an oxidation state of 0 and when it's reacted + 2 — so that
has been oxidised - as it's oxidising - oxidation state has increased
- and it has er - lost 2 electrons - copper - when it's in the
compound it is + 2 and in the elemental it's 0 so that has been
reduced - so what has actually acted as the oxidising agent - must
be the copper sulphate I suppose - as it's been reduced [writes].
6(d)(i) 020 [Reads aloud - interpolating "oh dear" midway] - think about
iron(XI) sulphate - well perhaps - there's either of two things that
could happen - the water - or the crystals could be driven out or
- sulphur dioxide could be given off - I suppose - a reasonably pure
product - because of the nature of iron(II) sulphate - evaporation
- why - ? [unclear] if that was right what do you think this
precaution might be - you'll have to - very gently I suppose - it
says how might this precaution be taken - well perhaps it reacts with
water - iron(II) sulphate - I'll have to think - iron(II) sulphate
[in a whisper] - well it can't - no - it can't become iron(I) -
sulphate 'cause there's no such thing - I don't suppose it could
become iron(III) sulphate - possible I suppose - how might this
precaution be taken - well if it was heated gently - how might this
precaution be taken ? [unclear] - oh well I'll put that anyway - I
can't think of anything else [writes] - it will be heated very gently
- doesn't really make sense - how might this precaution be taken -
well it would be heated very gently - I don't know - I'll leave that
blank -
- A178 -
6(e) 020 [Reads aloud - Ex explains that this is unrelated to part (d)]
- explain why there was a difference between the actual yield and the
calculated yield - no idea - [Ex establishes that 020 does understand
about calculated/actual yields] - well - all of it might not have
reacted to start with - not if it was excess - it doesn't make sense
at all - well perhaps my original idea that some of it decomposes
- ah - perhaps it wasn't all the water - urn - might be two ideas there
- does it decompose to give sulphur dioxide or is that the three -
think it - oh dear - or maybe some water's driven off - what - despite
every care the mass of crystals obtained - than that calculated -
jumping out of the dish [querying] - perhaps - remembering the
solubility of salt - that was less because part of it jumped out of
the dish - I think I'll put that actually [despite no evaporation
to dryness] - neither of the other two seem to make sense [writes]•
7(a) 020 [Reads aloud] - well I expect it means - either loss of electrons
[writing] - yes it must mean loss of electrons - I suppose I could
put increase in oxidation state - no it must be loss of electrons -
7(b)(i) 020 [Reads aloud] - Fe plus plus plus - does it mean Fe 3 plus - II | | 2+
haven't seen it before - plus H [Ex confirms Fe = Fe ] - em -| j _j_
plus H -that must mean in the elemental form - Fe plus H - well
that has - gained an electron - gone from 3 to 2 - therefore it has
been reduced - so the hydrogen which has gone from 0 to + 1 has been
oxidised so - underline the hydrogen - well - ? [unclear] - that's
right - 2 Cu + bromine might work out the oxidation states again -
copper in the elemental form 0 — to plus 2 — that's been oxidised
— check that the bromine's been reduced — 0 to minus 1 - yes — that's
been reduced.
A179 -
7(c) 020 [Reads aloud] - name the Industrial process - ah - I suppose it
means things like the contact process - and things like that.
7(c)(i) 020 [Reads aloud] - that's sulphur dioxide to sulphur trioxide -
that s the contact process — it doesn't leave much space so — it must
be the contact process.
7(c)(ii) 020 [Reads aloud] - ah - can't remember what it's called urn [but
clearly knows she knows] - Haber process - yes that's right - that
was memory.
Ex Yes - were you thinking of it as a catalytic reduction?
020 No ~ not at all - [agrees with Ex that it was the N to NH^ and
voluteers that she just ignored the catalytic reduction] .
8(a) 020 [Reads aloud] - oh - s' - st' sterate I remember - sodium
sterate or something like that - pure soap - well when you produce
soap - you take - steric acid or something like that - yes - sodium
sterate [however spells it correctly].
8(b) 020 [Reads aloud] - [sighs] - because of reaction [writes as she
speaks - agrees it is straight out of the notebook] - between - the
stearate compound and the calcium/magnesium compound um - either the
sulphate or the - or hydrogencarbonate - to produce - insoluble scum
- and lather is only produced - when - soap is in excess.
8(c) 020 [Reads aloud] - oh - well when you heat hydrogencarbonate - you
get water, carbon dioxide and the carbonate - now what's the test
for carbonate - oh yes - bubbling carbon dioxide through it - but
would that work with the sodium hydrogencarbonate as well - ah -
well when rain falls that contains - hum - if you heated the sodium
- A180 -
carbonate you'Id get the oxide - and the carbonate - urn - I think
it's - oh - is sodium hydrogencarbonate - sodium carbonate is soluble
- sodium hydrogencarbonate isn't - is that a chemical test or a
physical test - hum - don't think I'll put that - it seems a bit
physical — [sighs] — I think the original idea of heating sodium
hydrogencarbonate — [starts writing] — heat the sodium hydrogen
carbonate and it would urn - decompose - giving off water, carbon
dioxide um — and carbonate — it would give off steam whereas the
carbonate wouldn't - does sodium carbonate decompose - that's a point
- I know the hydrogencarbonate does - yes it does - [writes on] I'm
writing heat the carbonate and it would produce no water, only carbon
dioxide - [Ex points out that the Na2C03 is hydrated and 020 realises
at once she is wrong - Ex asks for further ideas] um - solubilties
again I suppose - something to do with um - that process that's used
to produce whatever it is with all those equations - you use the fact
that - sodium carbonate I think it is - you use the fact that sodium
hydrogencarbonate isn't soluble - but is that a chemical test - I
don't know -
Ex Well - no just solubility wouldn't be.
020 No - um - physical test I think.
Ex Yes - why did you try heating - .....
020 Well I can remember in my chemical tests - sort of distinguish
- and there's something about heating but I can't remember what it
was -
Ex You think you've got this somewhere in your notebook - this
particular distinction?
020 Yes [confirms this in further conversation].
9(a) 020 [Reads aloud] - I only know one - that's alkanes - alkenes it'll
be because it ends in ENE - [writes]
- A181
9(b) 020 [Reads aloud] - try being the operative word - [Ex explains
propene is analog of propane/ethene which 020 seems to understand]
- ....oh well there's carbons -
Ex Which you've put down in a row there.
020 Yes - and six hydrogens -..... that means they've all got 4 bonds
but 8 hydrgens so that can't work - I suppose it could be - double
bonds — double bond there — would mean that that would need — only
2 hydrogens - that would need - 2 hydrogens and that would need 3
- which isn't right either - if we cross that hydrogen out and put
a double bond there [has changed -C -C = C- to C = C = C-] - 1, 2, 3,
4, 5, 6 - they've all got 4 haven't they - 1, 2, 3, 4 - 1, 2 , 3 , 4 -
1, 2, 3, 4 - yes that's it - pretty like that - yes.
9(c) 020 [Reads aloud] - no idea.
Ex -have you any idea what might be made from ethene?
020 No - no idea - ethene -
Ex Used to be called ethylene - does that give you a ?
020 Alcohol [questioning].
Ex - try (d)(i) [abandons rest of item].
9(d)(i) 020 [Reads aloud] - a compound [writes at once] - made - from hydrogen
and carbon only [agrees with Ex that this is straight recall from her
notebook].
TAPE ENDS
PUPIL 021 - TRANSCRIBED PROTOCOL (TEST 03)
1(a)(1) 021_ [Reads almost silently] - well that's the first electrolysis we
did - that was called electrolysis of water at the time - er so It's
oxygen and hydrogen formed - er the one at the anode will be oxygen
which I 11 write down because — that1s what we learnt when
qualitatively examining electrolysis very early - the one at the
cathode we're told - would be hydrogen - which I'll write down now -
which follows of course because — hydrogen — hydroxonium ions are
positively charged and the cathode is negative [Ex establishes that
the last bit is simply rationalisation and asks how 021 knew which
was which] - oh - I remembered that - one of the first thing we wrote
down about electrolysis was - qualitatively - saying that at the anode
there's a non-metal - especially oxygen or chlorine - and - or the
anode dissolves and the cathode it's a metal or hydrogen deposited.
Ex I see - you had a sort of memorised rule?
021 Yes. [Ex encourages].
l(b)(i) 021 [Reads key points aloud thus] "volumes of gas - ratio of 2:1
[mutter] - always slightly less than half the other - why is a ratio
of 2:1 expected" - erm - well because the formula for water is H^O -
erm - well because the formula for water is 1^0 - erm - therefore -
and the - no, that's not right - the - in solution there will be
hydroxide ions and hydrogen ions being - er - released so - and both
gases are in fact diatomic - so the volume of gas by Avogadro's law
- will be - er the same - now let's see if I can er - in fact write
that down - er - yes for every two hydroxide radicals which are
neutralised [writes] - then - one molecule of oxygen - is formed -
and likewise for every two - hydrogen ions which are - neutralised
- no sorry I'm going wrong here aren't I - er - because at the moment
what I'm saying is that the volumes of gas should be equal - so if
- A183 -
I work backwards, if a ratio of 2:1 is expected then by Avogadro's
law - there should be twice as many molecules of hydrogen produced
- as there of oxygen - so what I think I'll try and work through is
to go for the neutralisation reactions and then - see what happens
- so - hydrogen is neutralised - hydrogen ion gains an electron -
to form a neutral atom then two atoms combine - to form one molecule
of hydrogen [writes equations as he speaks] - when - hydroxide ion
is neutralised it loses an electron — and becomes a neutral radical
er then two neutral radicals combine — [writing equation] — two
radicals combine - then one molecule of water is formed and one oxygen
atom and the two oxygen atoms combine - to form - one molecule of
oxygen - so - for every two hydroxide ions that are neutralised -
one atom of oxygen is formed and for every hydrogen ion which is
neutralised one atom of hydrogen is formed - both gases are diatomic
- s0 the number of molecules — will be directly proportional to the
number of atoms released - and therefore er since - two electrons
are required to neutralise - or to release one atom of oxygen and
only one - to release an atom of hydrogen - there will be twice as
much hydrogen as oxygen. [Ex excuses 021 writing out his answer
formally].
Ex - ..... was that something you hadn't seen worked out before -
why it had to be 2:1?
021 - er -
Ex - in other words was this argument something you've been through
before or something you were actually - generating as you went along?
021 I don't think that I'd ever actually - been asked - or we'd ever
actually worked through why a 2:1 ratio was expected except that it
was from Avogadro's law. [Ex encourages to continue in like vein].
- A 184
l(b)(ii) 021 [Reads aloud] — well this we undoubtedly haven't done — but er —
the reason I should imagine is because er - hydrogen - I'm writing
this down - is er - much less dense than oxygen - - erm - and it will
have be - to come off the electrodes more quickly - so that really
implies - so - that er - the forces between hydrogen molecules are
less than those between oxygen molecule - so that's - I work out from
information given in the question rather than - you know my own
knowledge and I've no idea whether that is correct - but er - it seems
logical -..... [021 agrees it is a guess which seems to be sensible
- and apologies for illegibility of answers] - right -
l(c)(i) 021 [Reads aloud] - erm hm - well there will be no increased rate
of neutralisation [writes] - rate -no, because the rate of
neutralisation is directly proportional to the current passed - er
- sulphuric acid - let me think er - sulphate ions are - not
neutralised as far as we know - er - hydrogen ions - oxygen -
hydroxide ions erm - are the only other ones present - so in fact
there should be no effect [writes] - that is, of course, assuming
that it doesn't attack the electrodes - which is presumably er - not
required in the question -
1(c)(ii) 021 - increasing the temperature of the sulphuric acid - well again
there'll be no increase in the rate of neutralisation [writes] -
same mass of gas collected - but the volume of the gases may increase
- from the er - gas laws ..... [chats with Ex but nothing
significant to add] .....
1(d) 021 [Reads aloud] - oh er - well conduction through a copper wire is
by movement of the free electrons — which of course doesn't happen
- A185 -
in an aqueous solution like sulphuric acid - er - so I'll put that
down first [writes — and agrees this is an explanation memorised from
his note book] — the conduction in a solution ~ er is by movement of
ions er - various terms strong and weak apply - er - strong
electrolyte — good conductor is fully ionised erm — so I'm remembering
various examples of the strong electrolytes - sulphuric acid was one
being 100/ ionised — or the conduction is by movement of ions [writes]
and by the receiving - and donating of electrons - to the electrodes.
2(a) 021 [Reads aloud] - erm ammonia is NH^ - the ammonium radical - which
er - is the - one involving the lone pair - accepting the extra
hydrogen is therefore HN^ - the er valency I remember is - er one -
the valency of the carbonate radical is 2 - therefore the formula
will be NH^ twice CO^ [021 agrees that in fact he knew NH^ at once
and the lone pair business was rationalising].
2(b) 021 [Starts to read aloud] - "formula Nl^" - ..... hm - .....
NH2 I didn't think there was a radical I wondered if it was a
misprint for NI^- er
Ex Well it isn't!
021 Well having - presumed then - can be obtained from ammonium
carbonate - I've never come across urea in chemistry at all - how
could you prove that the colourless liquid obtained was really water
- er - well - you could find it contained water by putting er cobalt
chloride paper which turned from blue to pink but that is not - in
this case adequate - you would have to find it was pure water by
finding it's boiling point - it should be 100°C [writes]. [Ex
establishes that 021 has previously encountered a case - condensate
from heating CuSO^.SI^O in form III - in which B.P. was used to show
a product was, rather than simply contained, water].
2(b)(ii) 021 Urea is a covalent compound which - means sharing of electrons
- er try to draw its structural formula - yes well I haven't drawn
many structural formulae and - so I'm totally unfamiliar with the -
Ex Well - what do you understand by structural formulae?
021 er - formula which is - er a formula in which you connect the
various symbols which represent atoms - er - by single lines to
represent covalent bonds - er - and -..... the formula indicates
that there is a radical - nitrogen has a valency of 3 I remember
and hydrogen 1 of course - so if you draw the two radicals Nl^ to
start with - [draws] - and see whether they in fact connect - er
- to CO - well the nitrogens will have another bond free - carbon
will have 4 bonds - oxygen two - so - if - carbon has to have 4 bonds
- then it seems logical that it will have a double one - somewhere
and presumably with the oxygen - er because it does form double bonds
with oxygen for instance in carbon dioxide and - then - one can see
that the two spare nitrogen bonds can then form ordinary bonds with
the carbon.
3(a) 021 [Reads aloud] - manganese(IV) oxide powerful oxidising agent used
to prepare — er several gases - and also as a catalyst of course
- er reacting with hydrochloric acid - er - I think it produces
chlorine - but I'll - have to test that by - consideration of the
chemical equation involved - an HC1 and MnC^ — manganese dioxide -
will form MnCl because - I remember that compound coming up several
times with an oxidising agent and manganese oxide - er if it's Clj
released that that should be next - and it seems logical that water
would also be produced - because hydrogen and oxygen are left - er
that seems the equation — I don't think I need bother to balance it
because I'm reasonably confident that that is in fact the case so
- A187 -
the name of the gas would be chlorine - oh suitable chemical test
- chlorine Is an oxidisig agent - tch - no easy way out with lead
ethanoate paper or - or something - so let me think -..... I'm
thinking of a list of standard tests here — an oxidising agent — will
- therefore decolourise - er potassium permanganate - solution - er
I remember that was one of the tests we did when we were working with
chlorine - and it also changes potassium dichromate paper from orange
to green - er - potassium permanganate [writing] potassium manganate
(VII) - and I think - it's systematic name is - from purple.
3(b) 021 Iron(III) sulphide reacts with dilute hydrochloric acid - ah yes
- this is a very old reaction - we've done it many times - it
produces the rotten eggs - hydrogen sulphide - [021 explains that
he remembers "doing it - yes"] - chemical test is - er - the one
which I in fact remember looking up - em - I'm sure of this one -
it is in fact the lead ethanoate paper [writes] - and er - it changes
from colourless to - a - supposedly black - deposit - ..... in fact
when we did it it was more brown colour.
3(c) 021 [Reads aloud] - now then this is the reaction er - it must be the
general reaction which, we were told, between ammonium salts and bases
- er produces ammonia - which would really be expected anyway - from
an ammonium salt - er the chemical test - for ammonia er - you can -
test it for acidity because it's one of the few alkaline gases but
there's a better test - I remember doing it - it was - a solution -
paper turns brown - Nessler's solution that's it [writes; agrees he
has a visual image].
3(d) 021 [Reads aloud] - well er - because of the test chlorine - is an
oxidising agent - er the others - hydrogen sulphate is a - a reducing
- A188 -
agent - er - and ammonia - I assume from its formula that it could
be a reducing agent but I - can't remember coming across it acting - ?
(unclear) -
4* 0 2 1 An experiment was carried out to find the approximate heat of
neutralisation — which we've in fact just done — er if I can remember
the results the - strong acid against a strong - base - providing
- the quantity of sodium hydroxide is the same - the heat of
neutralisation is the same - for the same quantities [continues
reading silently] - equal volumes of hydrochloric acid and sodium
hydroxide - and where's the concentration - 1M which means that they
should exactly neutralise each other because - er in one case - well
they both contain one - er hydroxide ion and hydrogen ion per - urn
- well they're both mono-basic or - I'm finding it difficult to
express -
4(a) 021 [Reads aloud] - well that must be simply the heat generated by -
or the heat generated when [writing] - er an acid is neutralised -
by a base - so that is simply what the term neutralisation means -
erm - but er - we really ought to attach qualitative value to it -
er quantitative value - erm - so particularly - when one mole of an
acid stroke base is neutralised - I assume that's what the question
means rather than just the general term - er
4(b) 021 [Reads aloud - oh well - we used plastic containers as well -
it's - because plastic has a - absorbs less heat - and therefore you
don't need to take into account the heat capacity of the container
[writes].
Ex Was this a reason you discussed when you did the experiment or
is this something you're presuming?
- A189 -
021 er - I don't remember that we discussed it In any great detail
but um - I know that plastic has a — is an insulator if has a - it
absorbs less heat from — liquids — that are contained in it [continues
writing] -
4(c) 021 In a second experiment nitric acid - similar to hydrochloric acid
- potassium hydroxide again — similar to sodium hydroxide — oh dear
explain why this is so - er - this is difficult - it's because in one
- 100 c.c. — the density - of hydrogen and hydroxide ions must be the
same - er - so - so they can - so the same number of hydrogen and
hydroxide ions to neutralise each other - er so - expressing that3
I'Id have to say that - in [writes] 100 cm of either potassium or
sodium hydroxide there are equal numbers of hydroxide ions and
similarly for the acids -
4(d)(i) 021 [Reads silently then aloud] - now er - sulphuric acid is dibasic -
H two S0^ so possibly a greater rise in temperature would be expected
3- er but no - because in fact 100 cm of sodium hydroxide is kept
constant - and that should be fully neutralised by - the hydrochloric
acid - so if there were more hydrogen ions they wouldn't be able to
neutralise any more hydroxide ions - so in fact the rise in
temperature should be the same - it just says what would happen so -
no explanation is asked for [writes].
4(d)(ii) 021 [Reads aloud] - ah now then - this is - again a monobasic acid
but it is a weak acid - and er - some of the - energy and - er this
was discussed - is required to ionise the acid - and so the
temperature rise would be less in fact.
- A190 -
5. 021 - number of electrons - and the mass numbers - ah number of
electrons Is also equal to the number of protons er - since the
atoms are in fact neutral as It says - er urn -
5(a) 021 [Reads aloud] — er the name isotope means the same place in the
periodic table - which means the atomic number will be the same which
means the number of electrons will be the same - tch - er therefore
I'm looking for two with the same number of electrons which will be
M and Q. Which I don't happen to recognise but - evidently - are
isotopes .
5(b) 021 [Reads aloud] - same group er similar chemical properties - it's
the outermost shell - er of electrons which - is beig dealt with -
er electron shells [writes] K er - contains 2 electrons, M - contains
8 er - next one, - N will also take 8 - right - so we're looking for
the same remainder when - that number of shells is taken away so,
I will write in the group number underneath - if there are 6 electrons
then - K2 - it'll be 4 - leaving 4 in the outer ring - if there are
9 - 2 - leaves 7 in the outer ring - 14 - take away 10 - now that
leaves 4 - so - I'll just check those two - there's 2 in K leaves 4
on the outside - 14 - 2 and 8's 10 - and 4 - yes - so those two in
fact must be in the same group - and there's no need to continue with
the others.
5(c) 021 [Reads aloud] - halogens are group 7 - chlorine etc. - and I've
already found the group 7 one which is G - er yes.
5(d) 021 [Reads aloud] - oh - well the best thing to do would be to find
out what X and L are - er - well let's find out what group they are
- A191
— K2, s 10 —so that's in group 6 — could it be oxygen — mass
number 32 — no — no — doesn't sound hopeful — what else is in group
VI - I'm trying to visualise the periodic table - erm - group VI -
it's the one next to the halogens er - no - I know oxygen's there
- what else is there — sulphur — could it be sulphur — that's it yes
- I remember the mass number of sulphur is 32 so that would be sulphur
- er now what is X - X is apparently group I - erm - adding the three
together we've got 16 er 18 - so it'll have one electron in the outer
shell — therefore in fact it'll be an alkali metal — having a valency
of one - so 1 can now - er find the formula 'cause it'll - urn -
something like ei
[writes] - right.
021 [Starts to read aloud] - "copper(II) sulphate" - that means we're
dealing with a - a displacement reaction - where copper would be
deposited - a reddish-brown precipitate - yes - [continues reading
aloud to end of (a)] - urn - excess of iron filings - iron goes into
solution - em - excess iron is the insoluble compound so you always
use an excess of the insoluble compound - otherwise - the solution
becomes contaminated with - the other soluble compound which in this
case is copper(II) sulphate -
Ex ..... are you referring back to something?
021 It's difficult to say ..... I think I was attracted by the fact
that iron filings were insoluble and one usually uses an excess of
an insoluble - reactant - then it can be filtered out.
Ex You say one normally - so you're referring back to some previous
experience where excess of reagent has been used?
021 Yes ..... probably er - reaction with calcium carbonate and
dilute hydrochloric acid or - something like that ..... er why was
- A192 -
an excess of iron filings used - well in this case it's to remove
[writing] - all the copper(H) ions from solution.
6(b) 021 [Reads aloud] - oh now that some what put - presumably it's
referring to the reddish-brown precipitate - but - I would have
expected - that to remain on the iron filings and I remember the -
experiment with the - precipitate reactions we did - er - reading
the question - a reddish-brown precipitate was formed and the mixture
was filtered - er well yes - they'll both be present - the reddish-
brown precipitate will be copper and the excess iron filings - it
looks as if it wants only one answer - but - I suppose if in doubt
you'd better put them both down - I'll put down [writes] - copper
and excess iron filings -
6(c) 021 [Reads aloud] - er - dealing with precipitate reactions - the
definition of oxidation - which we did - one of four is - oxidation
- er - ah - remember there's a rhyme - redox rules ole - so I'll put
olS down - .... o l € equals - oxidations - loss of electrons - and
the accent is, of course, the minus sign - so, oxidation is the loss
of electrns so - the oxidising agent would be providing electrons2+- er again - I resort to an equation - Cu must be gaining electrons
- because it is a positive ion - therefore the iron must be providing
electrons - and - er - so the iron is acting as the oxidising agent -
is that reasonable - iron is losing electrons and going into solution
- yes it is -
6(d)(1) 021 [Reads aloud] - "special precaution had to be" - ah yes now -
now this would be the risk of oxidising it up to iron(III) sulphate
- I remember we did various - er reactions and if the iron(II) salt
was heated in solution the iron(III) salt was formed - which is
usually a brownish colour - [finishes reading the item aloud] - well
yes - low heat to avoid oxidation [as he writes] - iron(HI) - yes
that sounds reasonable — pure product.
6(d)(ii) 021 Oh - how might this precaution be taken - ah - now then — again
this is way back in the third year where we're dealing with salt
reactions - erm - two ways of boiling off the filtrate - either
directly - using an evaporating basin on a tripod - and bunsen
burner or - erm by means of a water bath which is slower - but it
also avoids spitting of course - I'm not quite sure whether this
in fact applies - I shouldn't be writing it down yet - er - [re-reads
(d) i/ii] - by means of a water bath - heating evaporating basins -
would that be adequate - means that the temperature is kept down to
100°C - yes - I should say that was - probably reasonably adequate
- I cannot, off hand, think of anything else - which would be as
effective.
6(e) 021 [Reads first sentence aloud - second silently] - ah - in spite
of every care the mass of crystals obtained was much less than that
calculated from the balanced equation for the reaction. Explain why
there is a difference between the actual yield and the calculated
yield - er - now - doesn't mention quantities involved - er urn -
..... well I looked back to - check whether quantities were in fact
mentioned - what has obviously happened is that - somewhere along
the line - what was expected - or what was assumed to have happened
hasn't happened - which must be either the reaction didn't proceed
fully - or - that some of the crystals were lost during evaporation
- ah - again - I don't really know which one to go for. [Ex
establishes that 021 does understand what a calculated yield is] -
again from the reading of the question - it sounds as if -
- A194
a saturated solution was formed - and the solution cooled and crystals
were filtered off - it doesn't actually - well it suggests that there
is still some left in solution - I - wonder if that could be what is
required here - since it says despite every care - yes I would say
that was probably more likely - the fact that some of the iron(II)
sulphate was left in solution — 'cause of the need for — er the
substance couldn't be heated until dryness - yes I think that's
probably the most reasonable answer here - [writes] I don't really
think that's a very good question - because it's er - well I'm not
sure about that answer.
7(a) 021 [Reads aloud] - oh now this doesn't really mean much to me - oh
- oxidation — definitions — oh — it will be again — oxidation loss
of electrons I assume - what are my other definitions - er - removal
of hydrogen gain of oxygen or other non-metal - er there'll be one
more - yes - an increase in oxidation state - well that's a
theoretical concept anyway really - yes it will be in fact, oxidation
is - loss of electrons - so I'll put that down [does so] - seems to
be - is that all that's required here? - [re-reads question] - well
- from outermost shell I can put - because that is the only area from
which electrons can be removed - er [adds this; 021 confirms that
he is influenced by the space allowed] - yes - I can't think of
anything else that should go in there - that seems a reasonable
definition.
7(b)(i) 021 [Reads aloud] - er - well - iron 3 plus, plus H gives iron 2 plus
- being oxidised - again loss of electrons - our definition - what
about the iron - has the iron lost an electron -no, it's gained an
- A195
7(b)(ii)
7(c)
7(c)(1)
7(c)(ii)
electron — so it will be the hydrogen — losing an electron — becoming
hydro' — H ion — so it will be the hydrogen atom which is being
oxidised -
023. Copper and bromine — er — has the copper lost electrons — no it's
gained 2 again - bromine yes - it has gone negative - which I believe
is written in my file somewhere as er - meaning to - no - hold on
- that's wrong - to go negative's to gain electrons which is to be
reduced so it is the copper — which is being oxidised — yes — because
in the previous example of course the - iron was becoming less
positive - whereas the copper was going positive -
021 [Reads aloud] - ah well I'm weak on industrial processes -
021 [Reads aloud] - er urn - sulphur(IV) oxide and sulphur(VI) oxide -
now what are they - ah well - oxides of sulphur - there are only two
- so they must be SO2 and SO^ - ah - this is the - process with the
long tube and the - platinised asbestos wool in the middle - heated
er - [021 explains he is thinking of a set-up on the front bench] -
urn - so that is the industrial process leading to sulphuric acid -
again the diagram - which we have got in our book - shows - flow
lines - and it's called the er - the contact process - I think -
021 [Reads aloud] "..... " - now again that's reduction - gaining
of hydrogen - catalytic reduction - well the only process industrial
or - that I can remember in connection with ammonia is the Haber
process - so er - I'll have to put that down and hope it's correct
- it's the only one I can remember -
- A196
Hkfci
8(a) 021 [Reads aloud] - oh yes - again this is third year work - when
we were dealing with hard water — ah the various soap — molecule —
one end being hydrophilic and the other - hydrophobic - er it's a
compound of sodium stearate I seem to remember - it says a compound
so — I should be fairly safe with sodium stearate —
8(b) 021 [Reads aloud] — er — it forms a scum — a scum is an insoluble
compound - hard water - yes - a limestone - calcium - calcium ions
- erm — insol' — it must be an insoluble calcium compound — that's
it calcium stearate - is the insoluble compound - so it's because
the - sodium stearate [writing] reacts to form the insoluble - calcium
stearate - as a matter of fact I needn't put it is an insoluble
compound because it just asks why would it not lather - er -
therefore [writing] is not available for - [finishes silently].
8(c) 021 [Reads aloud] - oh dear - sodium hydrogencarbonate - is - remember
from my work -it's unstable to heat - it gives off carbon dioxide
- hydrated sodium carbonate - ah! - so in that - well that could -
I suppose - heat the two - the one which gave off carbon dioxide is
sodium hydrogencarbonate - but is there an easier method - both give
off carbon dioxide on contact with acids - er - sodium carbonate -
no - I can't remember any other - tests which were used to distinguish
them -
Ex You don't know any standard test obviously.
021 No.
Ex You immediately know that you don't know a test and you're trying
to work one out?
021 Yes - er - well I don't really like putting heat - because it's
not really a very convenient chemical test - er - let me think about
- A197
— what's the standard test for carbonates — yes react with acids to
give carbon dioxide - er - again - no test for hydrogencarbonates -
I've a feeling that in the Solvay process - one is more insoluble than
the other — but again that's — not really — very good because I think
its solubility in - brine and not in water again I — I can't quite
remember - so I'll have to - use the effect of heat - erm - yes -
..... [writes and speaks] sodium hydrogencarbonate - when heated -
gives off carbon dioxide - and - sodium carbonate - is er - one of
the very few carbonates which is heat stable -
9(a) 021 [Reads aloud] - oh, this is unfortunate because we've only just
started organic chemistry - ..... er - paraffins it's - one which
includes - methane - now methane is CH^ - the general formula - for
the methane group is CnH2 n remember that - I've just written that
in my file - so - sorry 2n + 2 - so that doesn't in fact fit - so ah
propene - now then - so that series - the methane series is in fact
the alkane series which I remember now includes propane - so could
it be perhaps that that hydrocarbon series - is called the alk -
ene - [on questioning 021 thinks vaguely he may have heard the word
before].
9(b) 021 [Reads aloud] - [after discussion with Ex in which little
knowledge of ethene is evident he decides to have a go] ..... er
three carbons which will presumably be linked in some form or another
- ah - now then - I remember that the methane - and the alkanes -
generally have single bonds between them — so I think if I put double
bonds in here [draws] - and then - ah yes - because each carbon will
then have - 2 extra free bonds on which a hydrogen can go - which
makes up the full number — yes that in fact looks reasonable —
- A198
9(c)(1) O n [Reads aloud] Yes - well [laughing] - [agree to answer as for
ethene] - ..... well I - yes - no I'd probably put down poly' -
polythene - which Is In fact polyethene.
9(c)(ii) 021 [Reads aloud] - [laughs] - now hold on, hold on - I seem to
remember something — because - I know from — my — project on the
petroleum industry that plastics and - those sort of things are called
polymers and I have a feeling there is a word polymerisation - which
is what I * 11 put down because er —
amazing what you know when you come down to try isn*t it?
021 “ polymerisation - because well haven*t got a clue apart from
that.
9(d)(i) 021 [Reads aloud] oh yes I know that one - it's - I've only just -
it's a compound of hydrogen and carbon only.
Ex - that's straight from the notebook or something?
021 Yes.
9(d)(ii) 021 [Reads aloud] - oh - well - if it's from ethane - ethane is a
hydrocarbon - er I've never heard a polymer called a hydrocarbon
before - well - it's a - 50/50 choice - I certainly don't know if
any other substances which are put in polythene - I dare say there
could be - well I'll go for yes I think because it's made from ethane
and ethane is a hydrocarbon -
TAPE ENDS
- Al 99
PUPIL 022 - TRANSCRIBED PROTOCOL (TEST 03)
1(a) 022 [Reads aloud] - anode - positive electrode so - hydrogen and
oxygen are formed - so it'll be oxygen at the anode because it takes
- gives electrons which the anode is short of.
Ex Right you considered hydrogen and oxygen - why hydrgen and oxygen?
9 2 2 Because I know that when you electrolyse dilute sulphuric acid
with copper - with platinum electrodes you get those two gases -
..... 1 remember it from an experiment which we did - so I'll write
down oxygen [does so] - well if it's oxygen , and hydrogen are the
two gases evolved - if oxygen's at the anode, hydrogen must be at
the cathode - so I'll write down hydrogen [does so].
1(b)(1) 022 [Reads aloud] - ratio er - [Ex encourages - to think aloud] -
I'm trying to think what I've learnt about the ratio - I think it's
because the valency of hydrogen is 1 and that of oxygen is 2 - and
oxygen needs twice as much - energy - to be released and so - only
half as much will be given off as the amount of hydrogen - so I'll
write that down [does so] - the valencies of the gases are 1 for
hydrogen and 2 for oxygen therefore oxygen requires twice the amount
of energy to liberate it so only half the amount is obtained.
l(b)(li) 022 [Reads aloud] - I remember being told that oxygen is slightly more
soluble in - water - than - in dilute sulphuric acid than - er
hydrogen is and so - some of it will dissolve.
Ex Do you remember being told that in connection with this experiment?
022 Yes - .... we used a Hoffmann Voltameter - so I'll write down
that [does so] - oxygen is slightly more soluble in dilute sulphuric
acid so less will actually be collected -
- A200 -
1(c)(1) 0 2 2 [Reads aloud] — well this would increase the concentration of
Kc)(ii)
i(d>
I
“ hydrogen and oxygen ions — and so ** more gases would be given off
- er - I've never actually done this - so that is just thinking
logically about what should happen — so I'll write that down [does
so] - increasing the concentration of the sulphuric acid will increase
the concentration of the hydroxide and hydrogen ions in the solution
and so more gas will be given off -
022 [Reads aloud] - never done this so I've got to think logically -
what would happen - increasing the temperature of a reaction usually
increases the rate — and so — probably — the same amount of gas would
be given off but faster - so I think I'll write that down - it seems
as good a bet as any [writes] - increasing the temperature of the
sulphuric acid should increase the rate of the reaction and the rate
of evolution of the gases -
022 [Reads aloud] - well when electricity flows through a copper wire
- it is because electrons move along the - atoms of copper from the
outer shells - but when er - the electricity's conducted through
the sulphuric acid - it's because it makes ions which - travel around
in the - solution -
Ex Now have you remembered that explanation - is it one you've come
across before?
022 Yes I've remembered that from - the text book - page - I remember
writing it down - [Ex probes further] - ..... I remembered the
conduction how it conducts through - solutions - and how it conducts
through wires from physics ..... they're separate memories being
put together - so I'll write down [does so] that in the acid the
electricity travels by the production of ions which move randomly
but are attracted to the anode where they are neutralised and - er
- A201
- the electricity then travels back, to the cell - er - through the
wire by - now I've got to think - I've not written anything about
- the - conduction through copper wire and it asks to explain - the
difference so I've got to say why they differ - now then - I know
how they differ but I don't know quite how to put it down — er — in
a way ions are still formed — they're — no — through the wire by
passing on of electrons [writing again] of electrons from atom to
atom. [Ex establishes that 022 does not recall seeing the question
before - encourages to continue].
2(a) 022 [Reads aloud] - well it wants to know — it's asking you whether
you know - the - symbols for the elements involved and how they are
connected - and I know that ammonium the radical - is nitrogen and
hydrogen in the form NH^ er - and I know the carbonate radical is
CO^ - carbon and oxygen - so I'll write that down - [does so] now
let me think of valency - the valency of the carbonate radical is -
two and the valency of the ammonium radical is only one - therefore
you'll need two - ammonium parts to one carbonte - so I'll put it
in brackets and put a 2 after it -
Ex That's fine - how did you get the valencies 1 and 2?
022 I knew the valencies of carbonate - I don't really know why I
do - I just know the valencies of the radicals ..... I just know
them.
2(b) 022 [Reads aloud] - well I don't remember doing this - so I've got
to think about it - wants to know - how you can get ammonium carbonate
from - water and urea - now question 1 - "how would you prove the
colourless liquid obtained was really water" - I've read the question
- A202
wrongly I think, [re-reads aloud] - yes - yes - they're telling you
that [after (b) - goes on to re-read (i) aloud] - well - how do you
test for water - well I know that water is neutral - should be neutral
to indicators - so it shouldn't affect any of the indicators - so
that will be one test - the test for moisture is also - cobalt
chloride paper - or crystals - I know this because we did it early
on the third year - and remember turning it pink with steam - so I'll
write down that because I think that is what they want to know - that
you can find moisture and tell what kind of moisture it is - so I'll
write [does so] - with indicators - water - would not react - with
- cobalt - chloride - crystals - there - should be a colour change -
I remember heating the blue - heating you - making steam under blue
cobalt chloride and turning it pink - so the pink shows moisture -
and the blue shows dry - [writing again] blue - to pink - yes -
2(b)(ii) 022 [Reads aloud] - covalent compound - that's bonding - covalent
compound is - ? [unclear] the electrons are shared - is it - shared
- oh no - this isn't what that means - isn't that - covalent doesn't
mean that - or does it - no - I'm trying to think where I've seen
this - yes I think I'll draw what I think is the - what I think is
the electron - er - patterns for this compound - ..... it wants to
know where the bonds are between the various elements — well NHj is
- by the sharing of electrons I think — so I'll put that and draw
a nitrogen atom with its outer shell with — six — six electrons —
well I'll add two hydrogens - it'll be two - atoms - er electrons
in their outer shells connected to it — that's NI^ — we have two of
those [draws those] - I'll draw that twice - now I don't know how
they're connected — and the carbon is joined to the oxygen — in the
same way I think — carbon having 4 electrons [drawing] in it's outer
- A203 -
shell - so oxygen can - can only give it 2 - so it must be joined
to the NH^ ~ twice - by the other two electrons - so I'll add the
oxygen's - the oxygen to it - and now I've got to think of the - I
think that nitrogen hasn't got - 6 but 5 in its outer shell - now
I realise -
Ex What's made you change your mind?
022 That it - that nitrogen has got 5 because it wouldn't fit with 6 -
there's no way it could be joined - and if it's got 5 it would — so
they're joined together and I'll draw a diagram showing the 2 when
they're connected [draws electron diagrams] - er - that's 1 - and -
show the different electrons of the 2 - via crosses and dots and then
the - the carbon and the oxygen - and then - I can put the 2 extra
nitrogens in and that's how I think it goes together. [Ex discusses
and asks him to convert it to a conventional structural formula.]
022 Well there's one bond between the hydrogens - the 2 hydrogens
to the nitrogen - so we get that - and that occurs twice - .....
[draws] - and the other nitrogen is joined to the other 2 hydrogens
in exactly the same way - they're joined to the carbon by - er - a
bond - is it 1 bond or is it 2 - I don't know - I'll see how many
carbon - no it's - 1 - and then the carbon is joined to the oxygen
- by a bond - but I'm 1 short - I should think the carbon must be
joined to the oxygen by 2 — ..... because I know it's only got 4 bonds
to give and if it had only got 4 it wouldn't give 2 to - 1 nitrogen
and 1 to the other - so it'll give them both to the oxygen.
Ex Yes - what's the valency of oxygen?
022 Oxygen's valency is 2 -.....
3(a) 022 [Reads aloud] - now I've never done this reaction so I don't know
from the past - what happens so I shall have to use my knowledge of
- A204 -
— er how these things react — to draw — to write an equation and then
work out which gas will be given off — well — manganese - isn't higher
than — hydrogen in the — electrochemical series because — well at
least I don't think it is — I've nev' — I don't know — but it doesn't
behave in other ways - like it is - so I'll put that it will react
because I don't think the question would — say this if there was no
reaction - so the chemical formula for manganese is Mn - oxygen is 0 -
the valancy of oxygen is 2 and that of manganese is stated to be 4 -
so it's Mn02 plus hydrochloric acid which I know is HC1 - I can
remember that - now there aren't - there's only one real possibility
it can be - and that's to form manganese chloride - and water or as
it's a gas it must be steam [writing equation] - now it doesn't really
matter about balancing the equation because - I only want to know -
what the gas is - we'll balance it just in case the examiner looks
how I've obtained the answer - we'll need 4 hydrochloric acids -
because it's MnCl2 water - or 2 steam - so the name of the gas is
steam - and the chemical test is - it leaves - it leaves indicators -
damp better put damp [writing] - damp indicators - neutral and turns
cobalt chloride crystals from blue to pink - because I know that -
I've just worked that out and I can remember it from the last question
3(b) 022 [Reads aloud] - here again I don't remember doing the experiment
- I probably have done but I don't remember - so I'll write an
equation because I think that's the easiest way - iron with a valency
of 2 - sulphur with a valency of - 2 - so that's FeS - and
hydrochloric acid again is HC1 - so the chances are it will be - oh
I remember now - I remember doing this - to make hydrogen sulphide
- so I know the gas is hydrogen sulphide - and iron chloride
[completes but does not balance equation] - hydrogen - sulphide's
formula is H2S because - hydrogen has a valency of 2 - er - I'll put
that as that might be relevant — and chlorine only has a valency of
1 and iron has 2 so it'll be FeCl2 so the name of the gas is hydrogen
sulphide — I shall write that in [does so] — and the chemical test
for hydrogen sulphide is — either it discolours — potassium
permanganate - from purple to clear - potassium permanganate solution
“ or it — also does something else with — potassium dichromate — it
turns it from orange to grass green - I remember that because it's
one of the very early things we did in the 4th year -..... I remember
it because I saw it happen when we were - dealing with sulphur - and
hydrogen sulphide.
Ex So when you were trying to remember it then - you were trying to
think what you saw - trying to visualise what you saw - or were you
trying to remember something you wrote?
022 No - I remember writing it down in my file - and I can remember
where I wrote it - so I shall put it down [writes] - it discolours -
I'll write potassium permanganate - it says in the question describe
one chemical test or a_ chemical test so that should be enough -
3(c) 022 [Reads aloud] - well I know this is how we produced ammonia in
the lab' because I remember doing it - I won't bother writing an
equation because I know what the gas is - so I'll just write ammonia
in - and a chemical test for ammonia is - let me think - it's an
alkaline gas - about pH 10 - I remember that - from when we heated
- bits of - protein - foods and got amino acids - heated the amino
acids - I don't do biology - but I understand basically that - .....
we did that in chemistry - so if it turns - if it turns universal
indicator to pH 10 - and has a pungent odour - that's not a chemical
test though and you want a chemical test — I should think that the
pH 10 would do - so I'll write that down - [does so] - chemical test -
- A206 -
turns - universal indicator - indicator to - pH 9 or 10 - yes - in
brackets I’ll put blue to purple.
3(d) 022 [Reads aloud] - well - ammonia can't because it's formula is NH^ -
so there's no oxygen there — steam can — because it's got oxygen —
but I don't know whether it's easily split up - er - it must be steam
though because hydrogen sulphide's got no oxygen so it can't be that
- it's simple enough - it doesn't ask for any explanation - it only
asks which one of these - so I shall write steam - and that should do.
[Ex goes back and asks supplementary questions].
Ex [Asks if MnC^ is familiar under its old dioxide name]
022 - well I've heard it as both - I've heard of the name [however
it was not felt to be "familiar"] - but I don't -
Ex You don't know what sort of substance it is?
022 I think it's a black powder -
Ex - anything about its properties? -
022 Oh is it - I think it might be - used in the production of a gas -
yes - it's used in the production of chlorine - .....
Ex [Ex now asks, re part (b), if he is sure that the gas and the test
belong together].
Ex Is the test you're got really the test for l^S?
022 I don't know - I don't know whether it's the test for hydrogen
sulphide or sulphur dioxide -.... [Ex asks to have another go -
given that KMnO^ is the test for SC^] -..... hydrogen sulphide -
..... well I'm trying to find something that'Id probably detect the
sulphide or just perhaps - the gas is acid - and might have a
characteristic colour -
Ex So you're thinking of properties of hydrogen sulphide -.....
A207 -
022 Yes - er well there's no chemical test which could distinguish
its colour I think - I know where it's found - it's found in bad eggs
and things - but I can't remember a test.
Ex You can't remember a standard test?
022 No -
Ex Lead?
022 - No - I don't remember doing that.
Ex OK lead ethanoate or lead nitrate.
022 No -.....
£22 [Starts reading aloud] - well I haven't done anything about this
so - I shall have to think logically to find any answers - [continues
to read aloud] - well I know what molar hydrochloric acid is - er -
and [finishes reading stem aloud] - well the basis of the experiment
seems pretty simple as I know that — I know what both the reagents
are - now the first question asks me - what is the heat of
neutralisation - so it's asking for a short - description of what
this is - well - I don't know - but I should think it's how much heat
is given out - when the - while the reaction takes place before the
sodium hydroxide neutralises the hydrochloric acid - I can't think
of any better idea so I think I'll put that down - the heat of
neutralisation - is the amount of heat - now amount of heat is
measured in Joules - I've done that from physics - I don't know why
- I just know that - but would it be connected to - possibly the
molarity or something but amount of heat - just amount of heat -
it just doesn't seem to be connected so I think I'll just put measured
in Joules - [writes] amount of heat measured in Joules which - is
given out - when - er an acid - neutralises - an alkali - or - vice
versa - that seems as logical an answer as I can come up with - second
question -
- A208
m
MM
4(b) 022 [Reads aloud] - now - I don't really know - I think I'll have
to guess on this one - could be something to do with not losing -
much heat through plastic - er - read the question again - [re-reads
stem aloud] - well I don't really know the reason - I'll just put
down - er - the plastic container was used to reduce heat lost -
although I don't think glass would make a lot of difference [in reply
to Ex's question as to how he guessed] - ....... I know plastic's most
plastics are rather good insulators - er but I - I thought glass was
a reasonable one - but I thought plastic must be a little bit better.
4(c) 022 [Reads aloud] - um - now - don't really know why they should be
the same - except that it's possibly the hydroxide - no - I don't
like leaving a blank but I don't really know -
Ex Have you been comparing the first experiment with the second at
all? - you haven't said anything.
022 Well yes I did actually - I compared sodium hydroxide with
potassium hydroxide - 'cause I know they're - because I know both
solutions are very alkaline - both caustic - and there's probably
not - a lot of diff»- "ence in them - because potassium and sodium are
alike - but I don't know about hydrochloric acid and nitric acid -
I know they're both the common acids - so they probably have quite
a lot in common - but I don't know really why - the rise in
temperature is exactly the same as in the first experiment - no
I think I'll leave that and think about it later - I think I'll go
^(d) 022 [Reads aloud] - um - sulphuric acid - an equal volume of molar
- so it's the same - strength - oh that might be something to do with
- the last questions - the molarity - they're both molar in
- A209 -
each case — so there's the same amount of substance there in the
solution — so the same amounts'll be reacting and so the same amount
of heat will be given out — I think that's probably the answer to
(c) - so I think I'll put that - [writes answer to (c)] - the
concentrations — of the two acid and the two alkalis are equal —
so - the reactions should give out the same ammount of of heat - yes
- [re-reads d(i) aloud] - [Ex interrupts to explain (c) so that 022
can make a sensible try at (d)] — ..... well the sulphuric acid has
always been compared with hydrochloric and nitric acid - in the lab'
up to now - so if it's - fully ionised - the ions will be - well
there's 2 hydrogens and sulphur and 4 oxygens so - well the others
are - a nitrate ion - so it must be a sulphate ion - and 2 - er -
hydrogen ions - so the reaction should be much the same as - in the
first one and the second one - as it's not the sulphate part of the
acid which is taking any part - it's the hydrogen - so - so the rise
in temperature - should be the same as the first one - I think - so
I'll write that down [does so] - the measured temp' rise would be
the same - now the - now it asks me - what would be the difference
with ethanoic acid - ah - I'm - not done very much organic chemistry
yet so I don't know -
Ex OK skip it -
5. 022 [Reads aloud] - gives the number of electrons and the mass number
- now the mass number is the number of protons and neutrons - yes - ?
[unclear] -
5(a) 022 [Reads aloud] - now what was the isotope - it's got a differing
amount of neutrons - but it's the same amount of electrons and protons
- because — there's no change in — charge so it must be one with —
two with the same amount of electrons - er - well there's only two
- A210 -
with the same amount of electrons as any other one - so it'll have
to be that one - so it's M and Q - it just says write their - letters
so I'll write the letters [does so] M and I think it's Q - yes.
5(b) 022 [Reads aloud] - well that means that one is going to have 8 more
as these are simple - numbers of electrons there's no complicated
configurations - I would think that they're going to have - 8 - then
n difference of 8 so that could be — E and 1 — or ? [unclear] —
yes it's got to be E and J - because they've got a difference of 8 -
Yes I'll put E and J [022 claims to have checked all other pairs] -
5(c) 022 [Reads aloud] - well a halogen has - seven electrons in its outer
shell - because the halogens I know are bromine, chlorine - fluorine
- well - they're as far as they go - ? [unclear] - s -
Ex -..... how do you know there are 7 electrons?
022 I know there's 7 electrons because I know where they appear in
the periodic table and I always picture the periodic table if I want
to know where something is - and try and remember where I've seen it
- and I've seen it directly to the left of - the noble gases - which
have - well - the first there have 8 - and so it has 7 - and that
means it must have an cold number - if it's got 7 - so that rules
out all but G and X - well - G's got 9 - now - well - wait a minute
- could be G - X has got 19 - that means it's got to have 12 somehow
- when you take the 7 off - so that's - take another 8 off - that
means you've got to have 4 - no it can't be G - er X - I would think
it'll be G - which'll be the one with 7 - 2 in the first shell and
7 in the second - yes I'll put G down.
- A211
(■MB
5(d) 022 [Reads aloud] - urn - X has got 16, X - well - take off - find out
what the electron configuration of L probably is - now I'll just jot
that down - I would think it'll be 2, 8, 6 - for L - and for X - will
- be 2 - 8 — 8 , 1 - yes - that's right - well 2, 8, 8, 1 is - is
it potassium or - I think it's potassium - and so potassium has got
a valency of 1 - er it'll be - the formula will be X 2 L 1 - or L
I think because - they will probably join - by forming 2 ions - X
will lose 1 electron and become positive and L wishes to gain 2 and
so we will need 2 Xs to give those electrons - so it'll probably be
X - I think X is a metal so we'll put that first - having worked it
out from its electron configuration - so it'll be X2 L - I think.
6. 022 [Starts to read aloud] - well that's a standard way - one of the
standard ways of producing crystals — now - why was an excess of iron
filings used - well - this is to make sure that - all the - in this
case - copper sulphate is used up so that none remains - otherwise
you could get copper sulphate crystals mixed - so I'll - I'll say
that - I just know that - [writes] because all the CuSO^ must be used
if a pure sample is required - pure sample of FeSO^ is required - yes.
6(b) 022 [Reads aloud] - well - what would be left in the bottom -
precipitate would be - iron filings - 'cause they would be - they
were all that weren't used so the name of the substance which had
to be filtered off before crystalising the solution would be - iron
[writes] brackets filings.
6(c) 022 [Reads aloud] - now - ..... I'm trying to think - well where
there's oxygen for a start — because there's obviously got to be
oxygen - now there's oxygen in the sulphate - in copper sulphate -
an — well there's nothing in the iron filings — so it must be the
- A212 -
- which of the subst' - it must be the copper sulphate - 'cause that's
the only one that's got the oxygen in it - or it might have been
the water in the - that's in solution - that the copper sulphate's
in solution - er - yes - water doesnt' usually react - as an oxidising
agent in that case - no I'll put copper sulphate [writes] copper
sulphate - the sulphate part - wonder if I should put that - no I'll
leave it.
6(d)(i) 022 [Reads aloud] - well sulphates - will decompose - 1 should think
that 11 be the thing, that it would decompose - I dont know - usually
in the production of crystals you have to be careful not to decompose
the - substance - by overheating so I should think that might be it
I'll put that - [writes] not to overheat the product and decompose
it - iron sulphate would decompose on - yes sulphites do decompose.
6(d)(ii) 022 [Reads aloud]- oh er - I wonder if I've put the wrong one or
whether they want to know - I should think I'll put - I'll agree with
my answer above and put - not to - to be careful on - to be careful
with the amount of heat applied [writes] - with the amount of heat
applied to the iron sulphate hm -
6(e) 022 [Reads aloud] - this could be because - er - some of the solution
was boiled away - yes - [Ex asks what he understands by the alculated
yield] - ..... well you can calculate the yield by using relative
atomic masses of - substances - and they would - you would do it by -
Ex OK - fair enough - .....
022 Now there's - must be lost - to the atmosphere - so I should think
It's by boiling the solution - that - this would happen - urn - I'll
put that I think - [writes] - because the solution may have been
- A213
boiled and some - if it's lost - I think that 'll do -
[Ex asks how sulphates decompose on heating] - .....
022 If you heat them strongly I think they give sulphur dioxide and
- the oxide of the metal - or the first part of the compound -
Ex And have you come across any techniques - earlier perhaps, in your
chemistry learning, for evaporating something without letting the
temperature get too high.
022 No - I don't remember - I was trying to think of that -
Ex Heating on a water bath for example.
022 Ah yes -.....
7(a) 022 [Reads aloud] - er - well I know from a little formula - little
word we were told to remember - that oxidisation is the loss of
electrons and - reduction is the gain - because we remember oil rig -
..... and I think yes - that's dealing with atomic level - the
electrons - yes I'll put that [writes] oxidisation is the loss of
electrons - doesn't ask for reduction so I'll leave it at that.
O L
7(b) 022 [Reads aloud] - Fe + H gives Fe - well which one's losing it's
electron - well if - iron is 3 positive it means it's short if 3
electrons - if it's 2 positive it means it must have gained 1 so it
can't be iron - it's the hydrogen losing 1 electron and becoming
positive - so it's - hydrogen - I'll write that down - and Cu - and
bromine - well the 1 one's becoming positive is losing electrons as
electrons have negative charge - and so - it must be the copper 'cause
that becomes positive - [writes].
- A214 -
7(c)(1) 022 [Reads aloud] - yes - now this is sulphur dioxide to sulphur
trioxide - which is in the process of producing sulphuric - [60
minutes up]. [later fills in contact process].
TAPE ENDS
- A215
PUPIL 023 - TRANSCRIBED PROTOCOL (TEST 03)
1(a) Q23 - the two gases are going to be oxygen and hydrogen — and oxygen's
going to be at the anode 'cause the anode's positive so I'm writing
oxygen - and the oxygen's negative - so the hydrogen will be at the
cathode.
Ex Now you said oxygen and hydrogen straight away - why?
023 I don't know - I think it was just reflex ..... on to two.
1(b)(1) 023 [Reads under her breath] - oh dear because - the ox' - the oxygen
- no the formula of water - 's H20 - it's always - 2 molecules - of
hydrogen to 1 of oxygen - so what's - the answer to that is - 1:2
- that is because - [louder] I'm writing the answer in - [does so
in silence] -
Ex Now again - why have you referred to the water there - because
it's dilute sulphuric acid?
023 Well in dilute sulphuric acid it isn't actually the sulphuric
acid that is electrolysed it's the water -
Ex And you knew that immediately?
023 Yes - it's one of those things that we were taught to learn -
I just seem to - recall these things - automatically -.....
l(b)(ii) 023 [Reads aloud] - this is another of these things we've learnt I
think - I think it's because the - oxygen - the oxygen dissolves -
I think - I think that's what it is - I'm not - I think I'm right
- [writes] the oxygen dissolves and there's less oxygen collected
than expected -
1(c)(1) 023 [Reads aloud] - constant temperature and pressure - the current
is kept constant - concentration - if you increase the concentration
- A216 -
— of an acid — you get a — the rate of reaction increases — suppose
that's what it means - so I should think that is what it is - so
there Id be — ah I don't know — the current — increase the acid
— the higher concentration of the acid — means there'Id be less water
so there's going to be - less gas is going to be evolved - less
of the gases — so I expect that's what that means. [Ex queries how
these answers were obtained but has to lead and nothing of value
emerges].
l(c)(ii) 023 [Read aloud] - if you're increasing the temperature - that's
anything to do with it - can't think about that at all -
increasing the temperature of the sulphuric acid - temperature,
temperature - I can't think of this one - .....
Ex Well we've getting a long silence now - are the wheels turning
over?
023 Well - I can't think of anything at all - I'm just having a
complete blank - temperature - no.
Ex - it's something you're unlikely to have been told or to have
learnt - it's something that I was hoping perhaps you might try to
think out -
023 - oh dear - increasing temperature - let me think - um - er -
I can't think of anything at all.
Ex OK - let's leave it - .....
1(d) 023 [Reads under her breath] - [re-reads] - well - in - the copper
wire - no - no ? [unclear] - well the electrons are passed through
the acid by ions - in the acid - hydrogen and oxygen - yes - sulphuric
acid - whereas in the copper wire they're - I'm not sure what they're
doing - they're actually travelling along the wire - I think it's
got something to do with that - I think I'll write that [writing] -
- A217
in the dilute acid the - electrons pass through via ions - ? [unclear]
- in the copper wire - I'm not quite sure what they do - in the copper
wire - ? [unclear] - in the copper they just - conduction - oh -
conduction - that's the wrong kind of conduction - mixing myself up
with my physics now - in some way - and just confusing the issue -
Ex The bit you've already explained - about conduction through er
- an electrolyte - that's a memorised explanation is it? - one that
you've used before or -
023 Yes - and I can also visualise that - what was it - I think it
was when we were doing the electrolysis of sodium hydroxide - no -
of brine - we - that was one of the - things that - we wrote down
- that, that is how the electricity will pass - through the
electrolyte - it's the same kind of thing because it's - electrolysis
- and I was just confusing myself with conduction - I was thinking
of heat conduction in physics - which isn't wrong - which isn't right
at all - electrons - ? [unclear] - copper wire - copper wire [in a
whisper] ? [unclear] - they just kind of pass along it's in a copper
wire -
Ex What is it you're writing?
023 In a copper wire the electrons just pass along it - and they -
but - I'm not - I don't - that doesn't seem right - I can't think
of - another thing [023 does not recall having done this item before].
2(a) 023 [Reads aloud] - ammonium's NH^ carbonate C O ^ - and ammonium's got
- a valency of 1 and carbonate's got - a valency of 2 so it's going
to be NH 2 C0~ - I remember valencies it helps me - it's much easier 4 3[than remembering formulae] -
2(b)(i) 023 [Reads aloud] - oh dear - we had something like this in the exam'
— and I can't remember — water — really water — I suggested before
WJW
IfiP
that you boiled it or something to see where it's boiling point was
- but I don't think that's reliable in case there's any impurities
in it - but I can't remember what it was — what the correct answer
was - um no - I can't think - I suppose that would have to be the
answer - seeing as I can't remember another one - water - properties
of water — water — I know that what I wrote was definitely wrong —
can't remember - how do you prove something's water - oh dear - um
- I suppose I'll just — have to write - what I thought was wrong -
what was wrong what I thought was right at the time - and get it
wrong again - ..... so I'll write that now [does so] -.....
2(b)(ii) 023 [Reads aloud] - if it's covalent then - that's when they share
- electrons - rather than give them up - to each other - and if urea's
NH four - two - twice - CO - so the NH twice - that'Id just be NH
twice - ? [unclear] - dear me - they're sharing - ? [unclear] - I'll
write that down it's a bit easier - write down the formula - usually
helps - NH twice - that's just -
Ex When you read the question - what did you understand when it asks
for full structural formula?
023 I'm trying to actually - draw - how - they would - um - how they
would be - um can't think of the word - draw - structural formula -
how they would look - or - ..... how the structure - the formula of
the urea would look - oh - that's not right - ? [unclear] structural -
Ex - are you thinking of diagrams with orbits of electrons and things?
023 No - it won't be that - because - I don't know any of the
electrons configurations or anything.
Ex So you're thinking of diagrams like that one for methane for
example [draws]?
023 Yes -..... CO - is going to be just CO - I think -
A219 -
Y°u ve drawn a bond between them there have you?
023 Yes - but I don't think I should have done - no I don't think
I should have done that - because - if you treat them singly - I mean
together - um - you're going to have two NH2s anyway - that's for
sure - because that's the formula - so I suppose it could be linear
I suppose - it's going to be something like that - but I don't like
that at all [has written NH2 - CO - NH2; Ex moves her on].
3(a) 023 [Reads under her breath] - gases - well - this - um - with these
acids - I've forgotten the name of them -the hydrogen is given off
usually - in most of the reactions - in the mineral acids - and the
chemical test for that would be a lighted splint - [writes] and to
see if it - with a lighted splint - there'll be a pop -..... that
again is just one of the things I've learnt — because you have to
learn them - so - that's that.
3(b) 023 [Reads under her breath] - dilute hydrochloric acid - iron
sulphide - write it down - see if I can write down the reaction -
and see what - ..... I'm writing the formula which is - for iron
sulphide - FeSO^ - plus hydrochloric acid - HC1 - gives - FeCl - 2 -
so that means - and -
Ex You've put 2 HC1 -023 2 HC1 - I've now balanced that out - and I'm going to get S02 's
the gas - sulphur dioxide [writes] - and I learnt - I think - I read
that last night - that it turns - which is what I'm going to write
[writing] - potassium dichromate - from - is it orange to green or
green to orange - I think it's orange to green because that's the
one I thought of first.
Ex Now, that's from learning it from the book last night?
023 Yes it is - it's just - stuck in.
Ex You don't think you've come across it before?
023 Yes - we've done it - I think - but I can never actually remember
doing this - it's probably when I was away - but - that's what I've
got written down - and I remember learning it also for the exam' -
and I wrote that -
3(c) 023 Ammonium chloride with calcium hydroxide - I find it easier if
I write down the formulas - I write down the actual reaction - .....
NH^Cl plus Ca(0H)2 gives - urn - of - C a C ^ - so I'll have to balance the ammonium chloride - .... because calcium's 2 and chlorine's 1
- the valencies - [Ex asks why CaC^] - well you'Id never get -
never heard of calcium ammonium - so - there's not much else it can
be really - plus - I expect it'll be ammonia and water - so - name
of gas is ammonia [writing] - its chemical test - chemical test for
ammonia - ammonia — well it's - oh no, that's ammonium — ammonia -
now then - is that - I'm trying to think of the reaction, between -
um - ammonia - I think it's ammonia - ammonia and HC1 - to give -
fumes of - yes, that's what happens I think - if you test - the
ammonia with - um - hydrochloric acid - you get fumes of ammonium
chloride - which is white - so you get white fumes - so that's what
- I'll write that now [does so] - and I can remember that from the
experiment we did - when we had two gas jars -
3(d) 023 [Reads aloud] - oxidising agent - hydrogen - acts as an oxidising
agent [writes] - because in oxidation - you either - give - take away
oxygen or add hydrogen.
- A221
4. [Agree to omit as this topic has not yet been covered in class - but
note that 022 did have a brief attempt].
5. 023 [Reads aloud skipping the table; re-reads under the table] -
that's it -
5(a) 023 [Reads aloud] - it's urn - atoms which have the same number of
protons but different numbers of neutrons - and the table gives the
number of electrons and the mass - number - well the mass number is
neutrons plus protons so - now - number of electrons - well the
number of electrons equals the number of neutrons - so it's going
to be - Q has got 18 electrons - ? [unclear] - which atoms - which
atoms - are isotopes of the same element - Q's got 18 electrons and
it's got a mass number of 40 - of 40 - it's got to be — no it's Q
and M - I think it's Q - it's M and Q because - they've both got equal
numbers of electrons but they've got different mass numbers - [Ex
queries how this matches with her earlier definition] - ..... no same
number of electrons - or protons - but different numbers of neutrons -
5(b) 023 [Reads aloud] - same group - now I'm not too sure on this -
because this is one when I was away — and I always seem to muddle
myself up with things like this - the same group - it's got the same
number of electrons in its outer shell — I think — that's right —
so - I'm looking for one with the same number of electrons - so E's
going to have 4 on the outside - G is going to have 7 on the outside
- J's going to have 4 - yes - L's going to have - 6 - M and Q are
going to have 8 - and Y is going to have - 1 - so it's going go be
- 2 - E and J -
- A222
5(c) 023 [Reads aloud] - halogens are the noble gases which are in group
8 - so it's going to be the one with 8 electrons in its outer shell
- which is M and Q - which are the same element - which we've just
decided.
5(d) 023 [Reads aloud] - X reacts with L - urn - valency - no when X reacts
with L - ? [unclear] going to have - X - something - well - they're
in different groups - that - that doesn't say anything about valencies
- but - if - if X - and L - form - a covalent bond - no that wouldn't
be right - I don't know - we've had questions like this before - no
- [Ex queries and discovers she had had a similar item for homework
7 or 8 months previously ] - ..... can't quite remember how to do
them - so I'll just hazard a guess at XL.
6(a) 023 [Reads quickly and softly - with skipping] - it's something to
do with solubilities - I think it's in the solubility of - is iron
sulph' - iron sulphate - is it soluble - sulphate I think it is -
it's something to do with solubilities - copper sulphate - copper
sulphate - this method - is - used - when - oh I know when the
solution you want to make - is soluble - the compound you want to
make is soluble - and that's why an excess is used - now - never
actually thought of that really - excess - oh I know why - because
[writes] - ..... you have to use an excess so that all of the
solution is used in dissolving -
Ex Is this something you've remembered from another occasion when
you've used excess of something or — or have you just worked it out
for the first time or -
023 I know that this method is used when the solution - when the
compound you want to make is — soluble ~ so — if ~ you've got to use
- A223
up all of the solid - so that's what I'm going to write - because
- no - ..... because all of the solid has to be - used - I think it's
the solid - it's either the solid or solution - all of the - all
of the solid has to be used - is it the solid - yes - I think it
is - I think it is - I'm not sure about that.
6(b) 023 [Reads aloud] - name of the substance - before crystalising -
well after you've crystalised - before - [reads part of item again]
- ? [unclear] - has to be filtered off - so - what you're crystalising
is actually the iron sulphate - so you have to filter off - the only
possible thing which is left - which is the copper - because that's
the only other thing there -
6(c) 023 [Reads aloud] - an oxidising agent would be - I'm not too sure on
oxidation and reduction because I've never actually done it - although
I did read it up before the exam' - I think that - oxidising agent
- well oxidation is - addition of oxygen - removal of hydrogen - or
- ? [unclear] - I think the iron's acting - because it's taking away
the sulphate from the copper - I think that's what it is but I'm not
sure on that -
6(d)(i) 023 [Reads aloud] - now - I'll read the question again [re-reads
part (d)] - no I'm not sure on this at all - we're making iron
sulphate - and that's what you're - evaporating - and - ? [unclear]
- not sure about this one at all — let me think — well there's iron
sulphate and there's water in it — so it's got to be something to
do with that -think - think - maybe it's a precaution that something
might be lost - I should - as you're - evaporate it but I'm not sure
- A22A
- or something might be gained - no I shouldn't think it's gained
- I should think - that maybe you lose something in this - [Ex
explains answer to (d)(i) and asks to try (d)(ii).]
6(d)(ii) 023 - to prevent oxidation - oh dear - prevent oxidation - so you've
got to stop any oxygen getting to it - so that it's going to stop
any oxygen - how do you stop oxygen - oxygen - how do you get rid
of oxygen - I'm not sure - oh dear me - [Ex suggests moving on].
6(e) 023 [Reads aloud] -
Ex This is nothing to do with oxidation and the precautions.
023 [Re-reading] every care - much less - why is it crystals is
less - so - probably - in the um - reaction between the iron and the
copper sulphate - maybe all of the iron - wasn't quite - gone into
iron sulphate - so - there isn't as much as they thought - no - that
seems a bit strange - crystals were much less - that's the only thing
I can think of - because - I shouldn't think that's all it is - but
- if you - - unless it's to do with the water - but I don't think
it is - [mutter] - I was just thinking about the formula of the iron
sulphate - water - I don't think it's evaporated - oh yes - that's
it - it's evaporated - so - no - no I'm getting it all confused again
with my physics.
Ex What were you going to say?
023 - well I was thinking - about - the evaporation - yes - I was
right - what I was thinking was that - you have to heat it to
evaporate it - and on heating - maybe more water - has evaporated
- than was originally - I thought - than the theory actually states
- so I should think that's what it is - so I'm going to write that
[does so] - because in evaporating the iron sulphate some of the water
may have been boiled off - evaporated - some there not some [writes
- A225
more in place of some] - this doesn't make sense what I've written
- because of evaporating the iron sulphate - if the water - some of
- no I've made a mess of it - because in evaporating the iron sulphate
[repeats] - more of the water may have evaporated - evaporated than
theory shows -
Ex You mentioned earlier in passing that iron(II) sulphate is soluble
- I wondered how you derived that - I don't suppose you remember
the names of everything that's soluble do you?
023 Well we've got a table - well we had a table in the 3rd year -
and I copied it out because I thought it would probably be useful
- for the 4th and 5th - and I just remember it — ..... I remember
- from the top - there's certain - things which are soluble and
certain things which aren't - and when it gets to sulphate it says
all sulphates are soluble except -..... and it isn't one of the
exceptions - I can't remember what they are but it isn't one of them -
7(a) 023 [Reads aloud] - I've no idea about this at all -
Ex You say you haven't done oxidation - is this because you were away
or something?
023 No - we've never done it in the class - .....we've never actually
sat down and done oxidation and reduction as a topic - and so he
suggested we looked in the textbooks before our mocks - on what it
had on oxidation and reduction - and I looked through it - but - I
never came across anything — about atomic level.
Ex - forget the atomic level - just tell me what you do know about
- oxidation - how would you define it forgetting the atomic level?
023 Well - oxidation is the addition of oxygen - to a substance or
the removal of hydrogen or - maybe addition of chlorine ~ and — let
me think - it's the oxygen's negative - so it's - um - oxidation is
- A226 -
the increase in electronegative - [Ex gives definition as loss of
electrons - it does not seem to ring a bell - asks her to go on to
try part (b)] .
I [ | 3+7(b) 023 [Reads aloud] - Fe - I suppose that's Fe - ..... plus H -
gives Fe+ + H+ - ? [unclear] - which is being oxidised - that's loss
of electrons - so - the one which is being oxidised is Fe because
— it's gone from Fe 3 to Fe 2 - 1 think - yes - that's right -
[underlines Fe++] - 2Cu + Br2 gives 2 Cu2+ + 2 Br - well that's the
Br - bromine - because that's lost electrons to the copper - the
copper's become positive - no - no wrong way round - [rubs out] - the
copper has lost the electrons because it's positive - so the copper's
been oxidised - because if it's lost electrons it's going to have2+more protons which makes it positive - [underlines Cu ] -
Ex Well you're right in saying copper has been oxidised but look at
the question, 023 which is being oxidised - no - I was right the first
time - bromine's being oxidised - if the copper is the oxidising agent
_ ..... [agrees in conversation that it has to be something on the
lefthand side of the equation].
7(c) 023 [Reads aloud] - oh dear me -
7(c)(1) 023 [Reads aloud] - oh - no I don't know this one at all - oxidation
- no - don't know.
Ex Well - can you try translating sulphur(IV) oxide and sulphur(VI)
oxide to - either formulae or to more familiar names? - .....
023 - sulphur(IV) oxide - sulphur dioxide - and sulphur(VI) oxide is
sulphur trioxide - so - now then - when have done this - we've done
this experiment when we do actually make sulphur trioxide - but
oh - I’m not sure about it at all - I'm not quite sure that
A227 -
catalytic oxidation is - oh I know it's got a catalyst in it - and
I know the catalyst is copper turnings - but that doesn't help me
at all - I expect it was in that um - table which I don't know - urn
- I think I'll have to go on to the next one.
7(c)(ii) 023 [Reads aloud] - reduction of nitrogen - oh that's the - industrial
process - I think that's the Haber process - because that's the only
process we've done with ammonia - and - nitrogen - synthesise it with
nitrogen and hydrogen - hm -
Ex Is it reduction - Haber process?
023 Well - it synthesises ammonia from nitrogen and hydrogen - so
it would be yes - because you add the hydrogen onto the nitrogen.
Ex Is a catalyst used?
023 Yes - I think it's rhodium - and platinum - I think - at 900°C -
[023 agrees that she did not use the phrase catalytic reduction at
all - even as a check].
8(a) 023 [Reads aloud] - oh dear - this is one of those things I can't
do - I think it - no - ? [unclear] - we did all this in the third
year and I seem to have mislaid my third-year file - which doesn't
help at all .....
8(b) 023 [Reads aloud] - oh god! - hard water - that's to do with the
solubilities - no it isn't - hard water - yes it is - because the
soap isn't soluble - isn't so soluble in the hard water - and that's
why you get — a scum — when you actually do the wash — in hard water
- I think that's what it is - because the soap - will not - dissolve
- in the water — because of the substances in the water — and in the
soap - which I can't think of either - the water - I can't think of
what the soap is - I think it - bound to have - calcium in it - it's
- A228 -
not calcium carbonate - or is it - no - that's limestone - um - oh
yes - the water's got calcium carbonate in it - I think - in the water
- I'm confusing myself - I think I'll have to leave that - [Ex asks
what she has written] - because the soap will not dissolve in the
water which - it stands to reason anyway - so that's just general
knowledge.
8(c) 023 [Reads aloud] - well I know that sodium carbonate will not
decompose on heating - but sodium hydrocarbonate will - 'cause that's
just one of my little - in my little hoard of information - so - if
sodium hydrocarbonate - is heated - it will - decompose - to yield
- sodium carbonate [writing] I'm not sure what else it is - I suppose
it's hydrogen - I'll put hydrogen - no it's a bit obvious - whereas
- sodium carbonate will not decompose -
Ex Well you're basically quite right there - let's just follow that
up a little bit if we may - if it's to be a test, then you need some
observable difference in the outcomes -
023 Um - ..... well - the sodium hydrogencarbonate would be different
in the beginning - to the sodium carbonate - and the sodium carbonate
would not change -
Ex You think one will change in appearance, the other won't change
in appearance?
023 Yes - [Ex queries further] - oh - the hydrogen being given off.
Ex I wonder why they don't use that as the lab preparation of hydrogen
if it's - sodium bicarbonate's - it's what your mother puts in cakes
023 ... I don't think it's - no - no let me think - let me write down
the reaction - that's what I usually do - um - NaHCO^ gives Na(X>2 “ no
what I am doing — sodium carbonate NaCO^ — oh — I know — you start
off - it's going to be 2Na - HC03 - no it isn't - yes it is - because
- A229 -
you have two sodiums - because - Na^CO^ - I'll start again -
2 NaHC03 gives Na2CC>3 + H20 + C02 - it's carbon dioxide that's given
off -
Ex ..... I wonder why you went for hydrogen being given off - have
you any idea?
023 - well I knew at the time it seemed too obvious - for it to be
hydrogen - and I didn't think it was hydrogen ..... and then I
thought - I didn't think it was right in the first place -..... so
the carbon dioxide can be tested with lime water [writes] - carbon
dioxide - is tested - with lime water - and the solution goes milky.
9(a) 023 [Reads aloud] - well we did this yesterday - I copied it up after
I came in ..... I think it's the alkenes - think - yes -
9(b) 023 [Reads aloud] - oh well it's going to be three carbons - in a
row I should think.
Ex Why should you think?
023 I don't know - er - no I don't think there is actually [Ex stops
and asks to return to original line of thought and not be swayed by
the question] - ..... no I haven't seen it - I think that's just the
way we - get used to doing them - but - I know what it is - no I don't
- I think - well if I put just the three in a row and try and draw
the hydrogens round the outside - then I'm going to have too many
hydrogens — and I'm going to end up with propane — so -
Ex You discovered that from the sketch you were - just trying to do?
[she has now rubbed this out].
023 Yes - I was just trying to draw that - so there must be - a double
bond in there somewhere - I think - between 2 - no, that doesn't make
sense - let me just draw it out - I'm going to draw a double bond
- A230 -
between - the first 2 carbons - so that means this - each of those
have got 2 bonds left - and the other one's got 3 [middle C has 5
bonds] - so that still won't be right so - by a process of elimination
- there must be a double bond between each of the carbons - so that
there's two bonds left on each carbon - for a hydrogen - which will
make the “ that's the only way I can think of doing it -
9(c)(i) 023 [Reads aloud] - well I don't know - [Ex asks the question again as
relating to ethene] - no because that's what they were doing yesterday
when I was in here - .....
TAPE ENDS
PUPIL 024 - TRANSCRIBED PROTOCOL (TEST 03)
1(a)(1) 024 [Reads silently] - anode is positive - so at the anode you get
the ions - hydroxyl and - sulphate, hydroxyl is - er - lower down
in the table than sulphate - hydroxyl will lose the electrons - no
hydroxyl's higher up in the - table - so it'll be lose electrons
easier than sulphate - so hydroxyl'll and form water molecules and
- oxygen ..... [writes; Ex establishes that 024 did know it was
oxygen before "working it out" - and asks him to think aloud rather
than rationalise].
l(a)(ii) 024 Well I know it's hydrogen - because there's no - er - the metal
ions - and you've got two hydrogen ions from both - the sulphuric
acid and the - because its dilute you've got water - so the gas can
be hydrogen .....
l(b)(i) 024 [Reads silently] - the ratio 1 to - is expected because water
is written down as l^O - two volumes of hydrogen to one of oxygen
- so that's what would be expected [writes] - water molecule is
usually written - written as 1^0 - and it can be seen that there's
two volumes of hydrogen — in two volumes of hydrogen to one oxygen
- reading part two now -
l(b)(ii) 024 [Reads silently] - can't say we've done this before - the reason
- [Ex asks to try to think aloud] - yes - I was thinking maybe
impurities ..... I would think it would be something to do with
impurities - to hold back a - nice - er - liberation of - oxygen -
or hydrogen for that matter.
Ex Have you worked out which one it is you haven*t got enough of or?
024 No - can't rally think why - [agree to leave it and possibly
return later] .....
- A232
1(c)(1) Q24 [Reads silently] - if you increase the concentration of sulphuric
acid you increase the amount of hydrogen ions — therefore you get
more liberation of hydrogen - [writes] increase in hydrogen ions -
and therefore - increase liberation of oxygen - eh - hydrogen [Ex
tries to get 024 to verbalise more] .....
l(c)(ii) 024 [Reads silently] - [Ex tries again to get 024 to verbalise] -
I would think it would hinder the liberation of the gases - [Ex has
another go] - no - I wasn't really thinking anything - I was - a bit
blank - ..... do you mind if I leave that one?
Ex No - .....
1(d) 024 [Reads silently] - oh - er - er the - conduction of electricity
through copper wire is the flow of electrons - along the conductor
- and through dilute sulphuric acid - you get the ions I think -
passing the electrons -
Ex Right -
024 So I'll write that [does so] - through the copper wire - the
conduction - is caused by a flow of electrons - but in the dilute
sulphuric acid - the electrons - the ions - carry the charge - to
each cathode - to each er - what do they call them those - electrodes
that's it - it's used at the top. [In discussion with Ex agrees that
this was the bringing together of two memories - from Physics and
Chemistry; Ex encourages further to think aloud].
2(a) 024 [Reads silently] - ammonium ion is NH^ with one positive charge -
carbonate is CO^ with two minus charge - and you've always got to
have a compound with - no charge at all - so you've got to balance
the charges with two ammonium ions - to one carbonate ion -
- A233 -
Ex Right did you remember the number of charges - you memorise lists
or - or what?
024 Yes - well - just remember er from when we've come across em -
writing [does so] - NH^ in brackets twice - and CO^ after the brackets
- reading (b) now -
2(b)(i) 024 [Reads silently] - so prove that the colourless liquid obtained
was water - add the liquid to anhydrous copper sulphate crystals -
and you'll see a change - a colour change to blue ..... I remember
doing a test - just to show the - colour change - I'm writing the
answer down [does so] - add the liquid - to some anhydrous copper
sulphate crystals - and a colour change from white to blue will be
seen if the liquid is water - there - reading two -
2(b)(ii) 024 [Reads silently] - structural formula - ? [unclear] refer to (b)
- you get - is the urea - we've never come across that before - [Ex
explains that it is not expected to be familiar ] - er - I would
expect the urea to be the Nl^ — so I'll have - where nitrogen — we'll
just have to - with - two hydrogens -
Ex So you're drawing this - now what are you thinking?
024 I was thinking if there was - how the structure could be carried
on - with the - another nitrogen joining the hydrogen - think I would
leave it at that -
3(a) 024 Reading 3 [does so silently] -
Ex Now as you're reading the question are you thinking anything to
yourself - you know - for example - this is about -
024 I was thinking that manganese(IV) oxide could be - be acting as
a catalyst or - as part of the reaction - ..... - can I just try an
- A234 -
equation ..... manganese dioxide plus hydrochlorine acid - er -
possibly go to - manganese chloride - and water - as steam - or the
manganese oxide - if it - catalyst - you could obtain hydrogen - and
chlorine - I would think it would be a bit too difficult - to split
up HC1 - I think steam evolved - due to an exothermic reaction -
[looks at equation again - has written MnC^ + HC1 only] - could
possibly get - hydrogen and oxygen - I would think oxygen - [Ex asks
why he settled on oxygen] ..... er I should expect - manganese
chloride - and - [024 agrees he is trying to juggle with the equation
and sort out what might happen] ..... well maybe if you get manganese
chloride and manganese hydroxide - then you could be left with -
oxygen -
Ex Fine - how about a chemical test?
024 - er relights a glowing - splint - 'cause we've done that before
- quite often - er [writes] oxygen will relight - a glowing - splint.
3(b) 024 [Reads aloud] - we've come across this before - we've done it
many - quite often - er the gas would by hydrogen sulphide - hydrogen
sulphide - you don't need explanation do you?
Ex No - that's all I need .....
024 er - chemical test - er the gas - er hydrogen sulphide - will
turn - lead ions - black - you can test it with a piece of filter
paper — dipped in some lead ions - and when brought near the gas
you'll see a black precipitate -
Ex You're remembering doing that are you - rather than _
024 Yes - there's a test for - yes the gas will turn [writing] - lead
ions - black -
3(c) 024 Reading (c) [does so silently] - we've come across this before
— there's the preparation of ammonia — ammonia [writes] ~ that — well
- A235 -
- we also know that the ammonia is the only alkali gas and the test
that we've come across is that it turns - damp litmus paper to blue
~ [writing] ammonia will turn damp litmus paper - blue.
..... when you remember a test — are you remembering it as
something you've actualy done - is that the way it occurs to you at
first - or are you remembering it from - er lists of tests or notes
of tests in your notebook or something like that?
024 Well - er - Mr. Hughes has gone through just lately the
preparation of the gases and the tests for them - so - we have been
through them before but we're supposed to - sort of recapped on it
- [Ex asks, for example for the H2S test, whether the memory is from
a book or of the test itself] .....
024 Remembering from the test.
Ex I see - and the same for the other tests -
024 Yes - well it isn't too hard to remember cause we've just recently
done gases and - .....
3(d) 024 Reading (d) [does so silently then aloud] - er - an oxidising
agent brings about loss of electrons - they're - referring to hydrogen
sulphide - because it's a compound - I would expect - the sulphide
ions to be oxidised to sulphur - do you get an explanation or - .....
[writes] normally - hydrogen sulphide - which would be oxidised to
sulphur.
4(a) 024 Reading 4 - [does so silently then reads (a) aloud] - we haven't
come across the heat of neutralisation before - [Ex encourages to
have a go anyway] ..... I'll expect to see - how violent a reaction
- er because of the neutralisation between the alkali and acid
[writes] - ..... er the - degree of hotness - due to the reaction
- between the acid and alkali - that's assuming it's exothermic -
- A236 -
Ex Yes - do you know if neutralisation is exothemic?
024 No - well - neutralisation doesn't require any heat to be put
into the reaction - so I would expect it to be exothemic [finishes
writing] — assuming an exothermic reaction -
4(b) 024 [Reads aloud] - possibly because - urn - maybe because the -
hydrochloric acid isn't strong enough to cause any - deformation.
Ex What would be wrong with a glass beaker then?
024 - er - would it be - subject to - er - alkali - I would think
- we've never come across this before - as why - a plastic container
is used - .... [decides to leave and come back later].
4(c) 024 Reading (c) [does so silently] - explain why the rise in
temperature is exactly the same as the first experiment - I would
think because equal volumes of both acid and alkali were used
Ex Even though it's a different acid and a different alkali?
024 well er - both acids were 1M - which assumes the same - dilution
- and the same for the alkali - yes - so I would expect the same
degree — of — temperature•
Ex Even though it's different substances that are reacting - both
different substances?
024 Well if there's more than one I would expect - an increase in
temperature - [Ex decides to go on to item 5].
5. 024 Reading 5 - [does so silently at first] - I m (familiar/
unfamiliar) ? [unclear] with the tables - electrons and stuff -
5(a) 024 [Reads aloud] - [Ex asks to verbalise] - er I was just comparing
electrtons of mass number - because as an element - electrons -
because it's an element - electrons are the same number as protons -
and - an isotope - has got - is it an isotope with the same number
of - the same mass number - I think it is - we're gone through this
very vaguely - I think isotopes is er - elements with a same mass
number and according to the table Q and X - have not the same mass
number - so I think it was Q and X -
5(b) 024 [Reads aloud] - looking at the er - number of electrons - I would
say M and Q - because - well in the structures you're got - 2, 8 and
8 - so that you need - so they're both inert gases -
Ex OK - let's quibble a little over part (b) - for the sake of
argument - if they're both 2, 8, 8 you could say they're both the
same element - and it says which two elements are in the same group
024 Aye - they'll be isotopes those will then - that's what I wasn't
quite sure about — I would expect M and Q to be isotopes ~ so can
I correct .....
Ex Oh yes - sure - yes if you'Id correct it in the exam correct it
now — could you explain why you're suddenly corrected it though*
024 Because the - it's the mass numbers - that are different with
isotopes -
Ex Before you said mass numbers were the same*
024 Yes - the - I wasn't quite sure - so which two elements - I wasn't
quite sure — so which two elements — I would think ~ E and — L because
they're both got - 6 electrons in their outer shell - so they both
take on a 2 minus charge - no - sorry -
Ex Tell me what you're doing
024 - er - number of electrons - will give - well if they're both
in the same group they'll both have the same charge - take on the
- A238 -
same charges as ions - so - I was just seeing - looking through the
number of electrons - which - which would take on the same charge
- could be referring to the number of electrons in the shell - you
would have - two in the first - four in the next - so that would give
a — four positive, four minus charge [must refer to E] - I would have
- two, 8 fill - that'll be one minus charge - I would think E and
J because - E would take on a - 4 positive or 4 minus charge - and
so would J - ..... J's got 2 electrons in the first shell, 8 in the
next which is bringing it up to 10 - and then 4 - yes - E and J.
5(c) 024 [Reads aloud] - well I know the halogens are those with -
fluorine, chlorine - bromine and iodine and astatine - and -
Ex Now how are you going to do it?
024 - well - each er all halogens will take on a - one minus charge
- so I'll just look for - which - electrons is - would give one minus
Ex Yes — how do you decide which ones would give one minus?
024 By referring to how many electrons - make up - the - how the
shells are arr - how the electrons are arranged - in the shell -
Ex Yes - sort of do it aloud as you - as you -
024 So I know - I've already done before - E'l take 4 positive - G
would take - that's 2 in the first shell - so I would say G.
Ex Yes - you're skipped a couple of steps there - .....
024 Yes - and then 8 in the next shell - to make a full element
er - full shell - which would be the ion - so that'll be ...... so
I' Id say G .
5(d) 024 [Reads aloud] -
Ex How are you setting about it?
- A239
024 X takes a charge - one positive because Q - Q which is before
it has got - full shell with electrons - it's got 2, 8 and 8 - that
makes 18 - and then - X has got 2, 8, 8 and then 1 - that - (take?)
a full outer shell it'Id lose one electron - it'Id lose one electron
- and form - one positive - and L - L has got a charge of - 2 in
the first shell - 8 in the next which makes 10 - then 4 so I would
say L X^ - because X would need - the four - L's got a charge of
4 positive or 4 negative and X has got a charge of one positive -
so you'Id require your 4 X - ions to balance the -
Ex Just check on the number of charges on L again will you - aloud
if you can.
024 - 2, oh sorry - yes - mistake - it's J that got's the 4 - [agrees
he was probably saying L but looking at J] - so L'll take a charge
of er - two - two - two negative - because - M's got a full outer
shell with - with the electrons - and L's got a deficiency of two
- so it would require two more electrons to make an outer shell - so
the - the compound would be X^L -
Ex Any reason you wrote it that way round rather than LX2 ?
024 Oh - I always write - a formula - compound - formula - with the
positive ion first .....
6. 024 Reading 6 - [starts to do so silently] -
Ex If you think of anything while you're reading please tell me -
024 er - reddish-brown precipitate - I would expect to be - copper
- [reads on] - iron's - iron file - iron’s got the - is more reactive
than copper — referring to the table — and so it'll form compounds
easier than copper would — it would — it can form its ion easier than
copper - and so it would take the sulphate from the copper - and form
iron sulphate itself - [agrees he has only looked at the "stem" so
far] ..... - so reading (a) -
- A240 -
*
6(a) 024 [Reads aloud] - er - an excess of iron filings used to make sure
that all the - sulphate from the copper(II) sulphate solution had
been removed from the - copper - as a compound - and so the filtrate
wouldn't show any copper sulphate - with the iron sulphate ..... so
an excess of iron filings used because [writes] - no I'll start with
so that - so that all the - sulphate - ions - are - joined - with -
the iron - and none - left behind - as copper - sulphate -
6(b) 024 [Reads silently; then aloud] - referring to the question - the
information - the name - er - the - substance which had to be filtered
off - was - the reddish-brown precipitate which was the copper -
[writes] the reddish-brown - the copper -
6(c) 024 Reading (c) [does so silently; then aloud] - that's the loss of
electrons - therefore - referring to the - the information - once
more -
Ex Could you do the thinking aloud!
024 — er — iron — the copper(II) sulphate acts as the oxidising agent
— because the iron loses electrons — the iron spelt IRON — the iron
loses electrons to form iron ion — which is iron sulphate — er the
copper(II) sulphate [writes] -
6(d) 024 Reading (d) - [does so silently] -
*
6(d)(1) 024 [Reads aloud] - haven't come across this before -
Ex Right - now how do you set about a question like this when you
haven't come across it before? .....
024 - trying to - see if I could think what - iron(II) sulphate -
was like - and if we've come across it at all before - and why there
- need be a precaution - do you mind if I leave that question? [Ex
agrees to omit part (d)].- A241
6(e) 024 [Ex points out that this is quite unrelated to the precaution
referred to in part (d) - 024 reads silently] - explain why there's
a difference between the actual yield and the calculated yield -
reading the information [does so silently] - might be that all the
- there might have been some copper sulphate left behind - [Ex asks
to think aloud] - copper(II) sulphate and water - they'Id show a
greater mass than copper(II) sulphate - which you - include in the
equation - when you're calculating the yield - and so the water is
neglected - and so you get a difference between the actual yield and
the calculated yield - that's what I would think anyway - [writing]
because in the - calculation - the - the water is neglected - and
so - the calculated yield - is different than the actual yield -
? [unclear] suppose anyway.
7(a) 024 [Reads aloud] - that would have something to do with loss of
electrons - the atomic - what does it mean by the atomic level? [Ex
explains that he cannot comment] - atomic level that - er -
Ex Are you going through other definitions of oxidation in your mind
and trying to decide what one's atomic level or what?
024 No, I was just - trying to relate (either?) between the protons
because that seems to — indicate something to do with protons — the
atomic level - 'cause I've come across atomic number - being - the
number of protons -
Ex You mentioned electrons are something to do with atomic - atomic
level?
024 No - never - come across the atomic level before - I expect it'Id
just be change in charge - because the - number of electrons - changes
and so - naturally the charge will change - because protons remains
the same - er - define oxidation in terms of changes at the atomic
- A242 -
level - the charge [writing] - of a - I would say - substance - no
if you say substance it implies a compound -
Ex Why are you dissatisfied with the definition in terms of loss of
electrons?
024 'Cause I can't seem to relate it to - anything to do with atomic
level - electrons -
Ex Well - aren't electrons atomic particles - er - part of the atom
rather?
024 Yea but the - as far as mass goes they're no part.
Ex Yes - does the question say anything about mass - OK [discusses
correct answer and asks to move on owing to shortage of time].
7(b) 024 [Reads aloud] - iron - iron three - ion - plus hydrogen - goes
to iron - two - plus hydrogen ion - so er - iron(III) - to iron(II)
- which is - reduction in this case - 'cause electrons are gained
which reduces the charge - so say - the hydrogen - loses - electrons
— so become hydrogen ion — so - I would say the hydrogen has been
oxidised - and the iron has been reduced - so underline hydrogen -
looking at (ii) - copper plus bromine - goes to - copper on - plus
bromine ion - so - copper - loses electrons - to - go to - copper
ion - because the loss of electrons is increase in the charge -
positive - and - bromine gains electrons to become bromine ion - which
is reduction - so the copper is oxidised in this case [underlines
this] .
Ex Why did you - work out what had happened to the bromine 'cause
you'Id already got that the copper was being oxidised?
024 Just to make sure.
7(c)(i) 024 [Reads alouud] - industrial process - would this be under the
topic sulphur - because we've done sulphur as the topic but we ve
never come across this.
- A243 -
Ex Well, could you find a more familiar name for sulphur(IV) oxide
perhaps - and sulphur(VI) oxide -
024 Sulphur(IV) - wouldn't be - er - two different forms of sulphur
- maybe - urn - we haven't done this before at all.
Ex No - sulphur dioxide and sulphur trioxide.
024 Oh yeah! - 'cause that's when you're obtaining sulphuric acid.
Ex It is - yes - go on - have you got the answer now?
024 - oo - what's the - industrial - is that when you obtain the
substance called oleum — it isn't the ..... [Ex confirms that 024
is on the right lines and 024 agrees that he now thinks he knows
it] ..... there's an actual process isn't there - made - nitorgen's
the Haber process - er -
Ex That's part (ii) is it?
024 - oh -
Ex Had you looked at part (ii) then?
024 No but that - that is - the names we've got processes - and that
- does sound familiar - the Haber .....
Ex We'd better stop there but - er - contact process?
024 Oh - yes - yes - yes .....
TAPE ENDS
- A244 -
PUPIL 025 - TRANSCRIBED PROTOCOL (TEST 03)
1(a) 025 [Reads aloud] - anode positive - so - oxygen - [Ex confirms and
queries] - anode's got a - em - needs electrons - it's got a
deficiency and - oxygen - is negative [Ex enquires further]
Ex ..... had you remembered this from a previous exam' question or
had you remembered doing it - in the class - where you remembering
it was oxygen - because - dilute sulphuric acid - there's no mention
of oxygen in the question - and yet you immediately knew it was oxygen
- I was wondering how you knew that -
025 'cause it's dilute - so there's - the negative ions are - oxygen
- and sulphide - so er - oxygen is i-
Ex Yes - I'm not trying to confuse you - your answer's right - I'm
just trying to get at how you knew it was oxygen.
025 Yeah - well I must have remembered but - it's the ones that are -
lower down that lose - quicker - lose easier and those higher up -
no - higher up lose easier, lower down gain easier .....
l(a)(ii) 025 [Reads aloud] - well it’s - in the water it's hydrogen and in
the acid it's hydrogen - so it's got to be hydrogen - [writes].
1(b)(1) 025 [Reads partly aloud] - er a 1:2 ratio - is expected - because
- er - in - water there's 2 volumes of hydrogen and 1 of oxygen.
[Ex asks that answers are not referred to him for confirmation].
[025 writes] - there is a 1:2 ratio of the gases in water.
l(b)(ii) 025 [Reads aloud] - ..... - urn - some of the oxygen dissolves
possibly - [Ex asks for source of this answer] - ..... no - it was
just a guess ..... because - well - hydrogen isn't soluble in water.
Ex Yes - why did you think about solubility at all - ......?
025 Well - I thought - when you boll a beaker of water - I just
remembered that - you get oxygen coming off first - before it boils
- so there's oxygen in it - .....
l(c)(i) 025 [Reads aloud] - urn - some - er - sulphide may go to the positive
because there's more of it than the - oxygen - ions [writes].
l(c)(ii) 025 [Reads aloud] - urn - [Ex asks to verbalise thoughts] - ..... I'm
thinking about er - equilibrium reactions - urn - er ..... I'm
thinking if it's exothermic or endothermic or whatever -
Ex Now why are you thinking that - how do you think that's going to
help you?
025 Well - so I know the temperature - what way the temperature's
going to affect it -
Ex - ..... how will knowing whether it's exothermic or endothermic
enable you to work out what difference the temperature will make?
025 - if it's endothermic you have to give - heat in to em - make
it go - whatever way it goes - whatever way is endothemic ..... I
don’t know. [Ex suggests as it is a trial question, having a go from
a diffrent point of view].
Ex - ..... what's happening - as the current comes through and
discharges ions here? - try picturing it in terms of the changes that
are taking place - we're told we've got a constant current and we've
increased the temperature.
025 Well the - hydrogen ions are going to the - cathode and the -
oxygen ions going to the anode — so I think ? [unclear] temperature
? [unclear] - I mean, would it just speed up both sides - by
increasing vibration - movement - [Ex refrains from reacting and 025
writes an answer based on naive application of kinetic theory].
A246 -
1(d) 025 [Reads aloud] - erm - when you pass it through a copper wire er
- it's the ion - the electrons that move from - er ion to ion - er
- from ion - er - ..... and er - dilute sulphuric acid - it's the
- free ions - that are attracted to the - the electrodes - and er
- electrons are given off into the electrodes and - off them into the
- into the er - ion or whatever it is [writes silently].
2(a) 025 [Reads aloud then writes answer without comment].
Ex You wrote that straight down, now - how did you get it?
025 Ammonium is 1 plus - carbonate is 2 minus - and er, you need twice
as many ammoniums to make it neutral — .••••• [Ex encourages to think
aloud].
2(b)(i) 025 [Reads aloud] - by adding anhydrous er - no, no - by boiling it
and seeing if it - if it boiled at - 100°C - at 1 atmosphere - and
er - if it froze at naught -
Ex Yes now why did you abandon the first answer you were attempting
- which also sounded -
025 - er - because - it might go - it might go to - it might go blue
but em - there might also be something else in it - ..... [writes].
2(b)(ii) 025 [Reads aloud] - um - no idea -
Ex Well - structural formula - what does that mean?
025 - what it looks like [Ex encourages to have a go] - .... em -
well - it's covalent bonds - and so there's sharing of electrons -
u m - .....
Ex Now - long pause - what are you trying to do?
025 - er - hydrogens got 1 electron so - er should be outside - er
bonded to the nitrogens - I think -
Ex So you've drawn a nitrogen with bonds to 2 hydrogen's - yes?
- A247
025 - um - CO - .... no, I don't know how to work this out - [agree
to skip it]•
3(a) 025 [Reads aloud] - er - name of gas - chlorine - er hydrochloric
acid is chloride ions - I remembered that one anyway - I think - [Ex
enquires further] — •••••• I think we only just did it a week ago —
..... chemical test - er - well it's a bleacher - so it'll bleach
litmus paper, damp litmus paper - [writes].
3(b) 025 [Reads aloud] - name of gas - hydrogen sulphide [writes] - .....
just remembered that - er test - turns lead ions silvery black
[writes] -
Ex Now can you give me any idea how you're remembering these tests
I mean - how do you set about remembering the tests?
025 - just remember them -
Ex Do you remember them as something you're doing - you know - the
actual - lead ions becoming black - or do you remember it as a sort
of phrase - so to speak?025 Well I just remembered doing it - just connect hydrogen sulphide
with that -
3(c) 0Z5 [Reads aloud] - ammonia [writes] - and the test is - er - the
only alkaline gas [writes].
Ex So what are you writing there?
025 - it's the only alkaline gas - ....
3(d) 025 [Reads aloud] - em - oxidation is the loss of electrons so that's
got to be - reduced - er - chlorine ..... well chlorine goes to Cl -
so it's - more reactive than - bromine and iodine - it's one of the
- A248 -
more reactive - er - halogens - and it's - the - if it oxidises - er ?
[unclear] - if it's an oxidising agent it itself's got to be reduced
- and that's gaining electrons so it goes to Cl - are there any more
- it says gases - does it mean which one or - does it mean - er -
hydrogen sulphide - turns lead ions silvery black - er - er I don't
know the equations for that so I don't know whether that's reducing
or oxidising - well lead's 2+ sulphides 2+ erm - [Ex asks to think
aloud] - ...... well - just working out what the charges on the ions
are - hydrogen sulphide's H^S - em - I don't know.
[Ex asks 025 to read question 4 and tell him if it is work that has
been covered as 024 seemed quite unfamiliar with it ~ 025 says no,
but Ex asks him to have a quick go at part (c)].
4(c) 025 [Reads silently] -
Ex Now you've got equal volumes, same molarity but a different acid,
different alkali but you still get the same rise in temperature -
why do you think that would happen?
025 - er - because it's - you've got the hydroxide ions and em - it
doesn't make much difference whether it's potassium or sodium - 'cause
the ions - ? [unclear] around dissolved in water -
Ex On the other hand though - you’ve got hydrochloric acid and nitric
acid.
025 Oh - .... oh well they're both - hydrogen ions - they're both
got hydrogen ions. [Ex discusses this with 025 and decides to go
on to 5].
5. 025 [Reads silently].
5(a) 025 [Reads aloud] - em - number of electrons - in the neutral atom
- would be the same as the number of protons - so - it'll - the number
- A249 -
of electrons would be the same but the mass number would be
different - so it's - em - 0 and X - 0 and X - [Ex corrects to Q] -
5(b) 025 [Reads aloud] - er - now it'll be - it's 2 in the first shell,
8 and 8 - so - working out the number of electrons - urn - - E and J
- I think - no - yes E and J - because there's er - plus 8 electrons
- one shell - [Ex asks for clarification] - ..... well there's - in
E there's um - 2 in the first shell and 4 in the second - and in 3
there is 2 in the first, 8 in the second and erm - 4 in the third
- so they're both - with 4 - in the outer shell - ..... [writes].
5(c) 025 [Reads aloud] - er there'll be one minus - whichever one it is
- so - that 'll be 7 in the outer shell - and that'11 be the 3 - no
- em - er - G - that's got 2 in the first and 7 in the second -
5(d) 025 [Reads aloud] - erm - X has got 2 in the first, 8 in the second,
8 in the third - and one in the fourth - so that's - X is 1 plus -
L - er - 2 in the first - 2 in the first, 8 in the second, 6 in the
third - so it needs 2 to get a full outer shell - so it's 2 minus
- and - it's got to be twice as many Xs to balance out - with the
L's - so it'll be X2L - [Ex encourages].
6. 025 [Reads partly aloud] - er - an excess of iron filings was used
so that - there was never deficiency of them - [writes] -
Ex Can you just expand on that a little — why is it important that
there shouldn't be a deficiency of them?
025 - erm - because all the copper sulphate wouldn't react - and then
- er you wouldn't get pure - er pure crystals - you'Id get them mixed
Ex I see - you don't think it's necessary to put that in your answer?
[No response, but 025 adds to his answer].
- A250 -
6(b)
6(c)
6(d)(1)
6(d)(ii)
6(d)
025 [Reads aloud] - er it'll have to be a solid — iron sulphate and
copper sulphate - no - copper [writes] -
Ex Yes - how did you work out the copper?
025 Erm iron's more reactive than copper and it — it takes the
sulphate from the copper - copper's precipitated.
025 [Reads aloud] - erm - the copper'Id be 2 plus - so - it would
be oxidised when it went to copper - so er - the iron filings acted
as an oxidising agent [writes].
025 [Reads aloud] - huh - [Ex encourages to verbalise] - could it
be something to do with the water? - er yeah - it was evaporated er
- until it was - saturated solution - or most of the water was driven
off and then er - possibly left to - to filter it er - to crystalise
- [writes] - er solution was boiled until most of the water was driven
off - and then left to cool and crystalise.
025 [Reads aloud] - I've just written that haven't I - so - [agree
with Ex to swap numbers around] - well so I've for number (i) -
switching round - so I'll put er - so that - the water that's - that
would be in the crystals isn't driven off - [writes].
025 [Reads aloud] - erm - well some water had to be lost - [starts
to write] -
Ex Sorry - what have you said there?
025 There's some water must have been lost when it was heated -
Ex Well it says despite every care - that certainly is a danger but
er -
025 Well - maybe - er - maybe the water just went off by itself erm -
- A251
Ex Yes - what are you thinking of there?
025 The 7 H^O - er - possibly no more heat - ordinary - room
temperature.
Ex What are you thinking of there - water crystalisation escaping
on its own - do you know of cases where that happens? ..... is
that what you're thinking of?
025 Yes - [agree to return to this at the end if time allows].
7(a) 025 [Reads aloud] - define oxidation - urm - well oxidation is the
loss of electrons so - something that's negative goes to positive
or something that's neutral goes to positive - or urn - oh -
Ex What's the "oh" for?
025 - I don't understand atomic level - urn - if that means when it's
er - when er the the atom is neutral - it's neutral atom - then it's
er - it goes positive - so I'll put that down [writes] - ..... er -
an atom loses electrons and goes positive.
7(b) 025 [Reads aloud] - er - well iron 3 goes to iron 2 - so that's
gaining electrons - that's reduction - and hydrogen goes to H - and
that's loss of electron so it's been oxidised [underlines H] - 2 Cu 2+ —+ Br2 gives Cu plus 2 Br - erm - copper's losing electrons so
that's oxidation - [underlines 2 Cu].
7(c)(1) 025 [Reads aloud] -
Ex What are you thinking?
025 er - haven't heard of that before - sulphur(IV) oxide and
(VI)oxide -
Ex Well you do know it - or you should know it - you're in the same
group as Mark are you?
025 Yes -
- A252 -
Ex - ..... try part (ii) and then come back to part (i).
025 Yes -
7(c)(ii) 025 [Reads aloud] - erm -
Ex Now again you're racking your brains - what is it you're doing?
025 - is that nitrifying? -
Ex Now what are you trying to do - I mean nitrifying is - you're in
the right field - are you sort of - in your - mentally looking at
pages of the textbook or? -
025 - thinking of the nitrogen cycle - [Ex encourages] -
Ex Sorry to keep badgering you but can you tell me what you're trying
to think? -
025 - [no response].
Ex [Tries to guide] - think of nitrogen in the atmosphere - it's
becoming ammonia NH^ - industrial process for doing that - very
important industrial process.
025 - is it the Frasch process? - no - or is it - could be -
Ex Thinking of names of industrial processes now are you?
025 Yes - urn - [Ex directs to part (i) again and suggest translating
the names into formulae or more familiar names] - .....
025 -urn - thinking of the oxidation - its loss of electrons.
Ex Yes - what's the formula for sulphur(IV) oxide - or a more familiar
name perhaps?
Ex Sulphur dioxide it is yes - and sulphur(VI) oxide is sulphur
trioxide - so - conversion of sulphur dioxide to sulphur trioxide
- does that sound more familiar? -
025 No.EX _ ..... that's the Contact process, used in making sulphuric acid
- and the nitrogen to ammonia was the Haber process - making ammonia
and then fertilisers.
025 I remember them now.
- A253 -
8(a) 025 [Reads aloud] - er - sodium stearate [agrees he just knew that
- but does not know any other compounds].
8(b) 025 [Reads aloud] - urn - because there's calcium or magnesium ions
in hard watrer and they form a scum -
Ex That again sounds like an explanation you're remembered - .....
025 - and that's - that's - that removes the stearate and that's what
- gives the lather - [writes].
8(c) 025 [Reads aloud Ex interjects encouragement to verbalise] - er
- sodium hydrogencarbonate - er that's soluble, sodium carbonate's
insoluble - um - hydrated - ..... er - don't know what you mean by
hydrated sodium carbonate - ..... water added -
Ex Means it's got water of crystalisation that's all - Na^CO^lOH^O -
025 - er both soluble erm -
Ex Earlier you said sodium carbonate wasn't soluble.
025 I was thinking of calcium carbonate - ..... er - gases given
off er -
Ex Gases given off when you do what?
025 When you heat them - if I'm thinking right at the minute - um
- thinking about the amount of carbon dioxide released - when you
add an acid - but I don't know - HO>3 is 1 minus - and carbonate is
2 minus - and is -
Ex What happens if you heat sodium carbonate?
025 Gives off carbon dioxide _
Ex And if you heat sodium bicarbonate - hydrogencarbonate?
025 - ..... can't remember - .....
TAPE ENDS
- A254 -
PUPIL 026 - TRANSCRIBED PROTOCOL (TEST 03)
1(a)(1) 026 [Read silently] - well yer - at first I think the anions probably
- er sulphuric acid - so it'd be er - hydroxide - oh er - yes - the
hydroxide - and - the - sulphate - and so - and sulphate's never given
off so it must be oxygen from the hydroxide given off at the anode
[Ex gives instructions and encourages] -
l(a)(ii) 026 State the name of - well I suppose it's - er it's hydrogen because
- both - hydrogen and water - form - hydrogen plus at the cathode -
Ex Right - you didn't know for certain it was hydrogen and oxygen
before you - .....
026 Well I suppose if I'd thought - on that - remembered it - because
we've done it - but - usually I do these questions as they come -
1(b)(1) 026 [Reads half under his breath] - yeah - well - ..... well -
because well — because — well - it's expected — do I write this down?
Ex Yes fine - but try to think it aloud while you're doing it.
026 Yes well - er - the oxygen is - the - which one is the one that's
double - I think it's the oxygen that's half - of the other - and the
oxygen is always slightly less because it dissolves in the water of
the voltameter — so - why is — [writing] because — the — er —
respective volumes — are produced as — er — as the same amount of
current * passes — oh ~ from — oh it can't be from the electrodes ~
passes through — passes through the electrodes - could I do an
equation for this?
Ex Yes - anything you like.
- A255
026 ..... well er, the - one of the electrolysis equations - I've
got to work out - OH - er plus - er - OH yes - it's got to be 2e
because er - the oxygen forms in a molecule - gives - oh no - 4e -
that's it - because it forms water and oxygen.
Ex You remember the 4 from writing this equation before do you?
026 Yes - although I - I sort of write -
Ex You're sort of half working it out, half remembering it?
026 Yes - er - so - so that's 40H - so that's the one that's half -
and - it's got to be the same amount of electrons so that they are
- as if it's balancing out because - the - er positive - er the anode
is giving off 4 where the - cathode's receiving 4 ..... so you get
- H30+ - oh - yes H30+ - plus 4e - so it'll have to be - 4 - gives
er - H^O - 4H20 - plus 2H2 - I hope that's - so we go on to the next
part - haven't we got any more space. [Reads l(b)(ii) aloud] -
Ex If you need any more space just use the margins or .....
026 [Reads his answer to part (i) under his breath] - well I may as
well carry on there — just to conclude — then — the — oxygen — er
forms - one molecule - to the hydrogen’s two - every time 4 electrons
pass - er pass through the electrolyte — or not that the electrons
it's not really the electrons - [Ex suggests moving on] -
l(b)(ii) 026 [Reads aloud] - well the oxygen - er dissolves in the water
Ex You said that right at the beginning - is that something you've
remembered from - having discussed this one before?
026 Yes - ..... [writes] .
l(c)(i) 026 [Reads aloud] - more sulphuric acid there'll be more ions - in
er - floating about - so you'll probably increase the rate of
production of the two equally - so increase [writes] - the - rate -
of - production - oh yes - production - of the - two - equally - well
- A256 -
here I'm sort of referring - I haven't done this - I'm trying to link
it up with rates of reaction - what we've just done - I'm not sure
if the rules are the same but .....
l(c)(ii) 026 [Reads aloud] - ah - I don't think that's got any effect - I'm
not sure - er - no - can't see that - I don't think so - 'cause I
don't think we're covered this - er -
Ex Well you've got the right answer, but how did you - decide that
it would happen.....
026 Well basically actually - I thought the current will have more
effect than anything on increasing it - er - I think that's basically
a guess -
Ex I see - you didn't know of any positive effect it would have ....
026 No but - I couldn't see if having any effect because - when we've
been doing - rates of reaction - temperature increases the - velocity
- of the - well the kinetic energy in it - and it causes collisions -
but I'm not sure that - this electric - this electricity is - so much
about collisions becuse it's attracting them -
Ex ..... so you did in fact build up a picture of what heat would
do and you didn't see that that was in fact going to make any effect.
026 Yes.
1(d) 026 [Reads aloud] - well through copper wire it's - the electrons
themselves in a cloud around the metal - are moving along sort of
- from - along the thing itself - whereas the electrons - er - ?
[unclear] go on indefinitely in copper wire - whereas in the
electrolyte - of sulphuric acid - in given amount - you're going to
have er - the - effect of this - the ions - some ions accepting
electrons - at the same time they're giving away - so you've getting
the effect of the passage of electrons - but really they're sort of
- A257 -
different electrons - and er - after a while it'll sort of stop to
happen after - most of the ions - that you can use - have been er -
have gone -
Ex Now again - this is a - a familiar comparison - you've made this
comparison before have you?
026 No [Ex interrupts] ..... yes - it's probably a bit long winded
for this space we've been given - so ...... - yes so - in the copper
wire [writing] the er - electrons - er - in a - cloud - better put
it in inverted commas I suppose - around - the metal - remain free
- and can move - along - well - the metal - when given an electrical
- I'm not sure - er using words - sort of that aren't really - I mean
like a push if I said an electrical push - I sort of put that in
inverted commas — can you use that in the — sort of a science context?
[Ex refers 026 to his chemistry teacher and asks him to continue as
if in a test] ..... well, I suppose I can't really think of any
other word — yes - given an electrical "push" — whereas in the — ionic
solution - well - oh I suppose - the ions - are - accepting - oh some
ions - some ions - are accepting - electrons - while - others - are
giving electrons - to the - circuit - er - which - has the - nett
effect - of allowing - a current to flow - let's look at the next
one -
2(a) 026 [Reads aloud] - 's NH - four - er - twice - CO - three.
Ex Yes - where did the twice come from after the pause?
026 Well the - we've been given the valencies of these things, and
I know carbonate is 2 minus - or I hope it's 2 minus - and er
ammonium is 1 + - so to balance out it had to be two - [Ex encourages
to explain this sort of thing] - I rarely remember formulas .....
although it's below - oh no it isn't - sorry -
- A258
2(b) 026 [Reads aloud] - [mutters] - water - ammonium carbonate - so here
we're getting - this urea seems to have lost two hydrogen - or is it
4 - 4 hydrogens - and two oxygens - so that's in the ratio of water -
2(b)(i) 026 [Reads aloud] - oh it didn't have any relevance anyway - er -
obtained was really water - er - really water - er - put in contact
with anhydrous co — er cobalt chloride — and if it turned er — con
- in contact - here I suppose it's just water not pure water - so
I'm just - hoping it's not pure - well it doesn't say so anyway -
with, anhydrous — er — co — cobalt chloride I think that s it —
chloride [writes] then goes - if water - it will change from - pink
to red - I think that's it - I can't quite remember - although I could
have used anhydrous copper sulphate - never mind -
Ex You mentioned pure - whether it was going to be pure or not - why
was that relevant? .....
026 Well er - I suppose if it says water - if it was pure I suppose
a more exact way was to boil it - at STP or whatever - see if it -
became steam - or boiled sorry - at 100°C - or froze at 0°C -
Ex I see — but you decided that wasn't required here
026 Not really - 'cause I think these exams are more exact - well
they're pretty - usually anyway - 's not - they say so - 'cause
they’re not really trying to fox you - what they're trying to do is
tax you -
2(b)(ii) 026 [Reads aloud] - well - I'm not sure about this - we don’t do this
much - we did a bit with er - what is it called - hydrocarbonates
- hydrocarbons - [Ex encourages to have a go emphasising that it is
not expected to be familiar] well NH2 - so I’ll probably have to do
- you use the C02 sort of as one blow - or do you have to do the C
- A259 -
and the 0 [Ex declines to comment] - ..... well I don't think I can
do the - full — - oh it's a full isn't - you see if I did this I
wouldn't know where to attach the - or whatever - to the CO -
so er - what I'Id have to do is really have a guess at this - putting
a C - oh yes - hang on - the C's got a double bond with an 0 -
Ex Now how did you know that?
026 -ah well - we've just done carbon dioxide - and - er that em -
so calcium's got 4 so I suppose - it's got 2 bonds left - so each
bonds going to go to a - 2 bonds are going to go to the - each of
the - whatever - the - I don't know - what's that - oh - I don't know
- to the compound that makes up the beginning bit - I don't know what
it's called - er - so I think it's going to be attached to the N -
which is going to - er itself - be attached - in I think a tetrahedral
sturcture - hang on that's 2 - oh no it's 2 sorry - not in a
tetrahedral - I was looking at the wrong one - it's just going to
be attached to 2 hydrogens - and the same at the bottom - the car
- one of the bonds of the carbon attached to another - not enough
space - hydrogens, so you get [has drawn correct structure by this
point] - so I think overall - we'll get a planar structure although
I'm not sure because — I suppose the single joints can move — so —
I think that's it - probably do another one to make it more clear
..... well at first I was really foxed by that but - suddenly when
I saw that one bit - sort of clicked -
3(a) 026 [Reads aloud] - well this is a base plus an acid gives - er - ?
[unclear] hang on, no that's wrong — oh dear — I always forget these
- gas — concen — oh concentrated — don't think I've done this — but
I guess chlorine — I'm not sure if it's right but — er —
Ex Where has that guess come from?
- A260 -
026 Oh hang on - hydrochloric acid - at first it was - I assumed that
because - usually - it's a guess really but - we've done these
oxidising agents and we've done sulphric acid - as - er - or was it
turning black copper sulphate to copper — I'm not sure ~ er —
sulphuric - I can't really remember that so - I'm not sure if
concentrated - it's a reducing agent - or is it an oxidising agent
really I'm a bit foxed here - just because I can't remember when
we used dilute - the effect - of concentrated sulphuric acid on copper
or was it - I think it was on copper - and it turned it to copper
oxide - so ? [unclear] oxidising agent - er - I wouldn't really know -
I Id probably have a guess - now that it's concentrated - at oxygen
- because - although that's an ionic bond and that's a - a covalent
bond -
Ex Sorry - what's an ionic bond?
026 ~ ionic bond - magnesium oxide - manganese - manganese - I don't
really know much about that either - I think it's a - that manganese
oxide is an ionic bond - and hydrochloric acid's a covalent bond
because it's concentrated - so I don't know - perhaps which bond would
prevail - probably - perhaps the er - now here I might hazard a guess
at chlorine again - because I've always thought that - covalent bonds
are weaker - and so chemical test for chlorine - gas - would be - er
- damp litmus paper - so if I had put chlorine - which I probably
would - er - test would be damp litmus pap - er put in damp litmus
paper into it - and if it's chlorine it should bleach it [writing
now] -
Ex The chlorine wasn't a blind guess - you had some reason at the
back of your mind for guessing chlorine rather than anything else
- do you know why you guessed it?
026 Well I thought it might well be - I thought at first it could be
this chlorine - because it's a weaker bond - the covalent - but -
- A261
that's about all 1 based it on really - I mean -
Ex You reckon the - HC1 bond is being broken - so that the chlorine's
released?
026 Oh er — yes — in a way I think — perhaps — the hydrogen may react
with - to become manganese hydroxide - .....
3(b) 026 [Reads aloud] - so this is a - sodium sulphide er - and a - dilute
acid - so - you should get - er - iron - ferrous - chloride and - er
hydrogen sulphide - so the name of the gas [writes] is hydrogen -
sulphide - I hope - chemical test for hydrogen sulphide - er hang on
- I can't remember this one - [Ex asks how 026 is tackling this]
..... well at first - I thought - of the hydrogen chloride test -
and that was - er - oh that was litmus paper I think - there's one
where we mix something - and dip it in a gas - I'm not sure which
gas it is though - oh no - I think no - that sorry - hydrogen chloride
test isn't damp litmus paper - it's er - silver nitrate and nitric
acid I think - it's a mixture of the two on a glass rod - and you
dip that in the gas and it goes white - the - with the precipitate
of silver - chloride - but hydrogen sulphide - I suppose you could
burn it - in er - limited supply of oxygen to give - er sulphur -
er - but the chemical test - I don't really know that one - it's
probably in a book somewhere - in my book but - I don't think I've
done it - er .....
3(c) 026 [Reads aloud] - name of the gas - so we've got chloride and an
alkali - oh hang on we've got an ammonium salt and an alkali - so
- that produces - ammonia - oh hang on - ammonia - I think it's
ammonia - so - er - ? [unclear] - er ammonia - I'm trying to think
what's happening to the chloride at ? [unclear] - calcium hydroxide
- HC1 - I suppose it goes into HC1 - but then what happens to the
- A262 -
calcium hydroxide - does that change - I'm prob - I don't know - it
could produce water and calcium chloride at a guess - er - chemical
test for ammonia - fff - I suppose the smell but that's not chemical
- er - tch - ..... er - chemical test - ammonia - oh er - oh no
that's another - no I'm afraid that's forgotten too.
Ex What were you - what were you thinking of when you said oh! just
now?
026 Well I suddenly thought of - ammonium - hydroxide - and - it's
only way to differentiate it between sodium hydroxide -
Ex Oh I see -
026 - it was a test and that -
Ex You're trying to think of all the tests you can?
026 Yes
3(d) 026 [Reads aloud] - so oxidising - so it - er - it makes something
oxidise - which gives away - accepts electrons - reduces - I always
remember reduces because it accepts rather than - it sort of adds
rather than reduces - so it's sort of opposite - so oxidising is -
given away - so it accepts electrons - hydrogen sulphide - erm -
hydrogen sulphide - well - amonia - hang on - there's other properties
of oxidisation - oxidisation er - is accepting oxygen and giving away
hydrogen - but those are sort of minor - characteristics I think -
so - the er - hydrogen one - er oxidisation is getting rid of - no
I don't think that one - er ammonium forms comp - er ammonium
compounds which is min - which is plus - so that's got - it's accepted
a hydrogen - and therefore got - er and it's got a positive charge
- um - positive charge and it's accepted a hydrogen so - must have
accepted a - sort of a virtually a proton which is a hydrogen - er
- whereas hydrogen sulphide when that reacts - [mutter] - (see?) -
- A263 -
I'm trying to think of it being burnt but - when it's burnt it gets
— it's er — in a limited — well I say in a limited supply it's -
Ex You're looking at (b) and (c) - what about (a) - have you
considered (a) at all?
026 Oh - no - I didn't really think er - 1 didn't think that was in
it actually - well chlorine I know -
Ex Why not?
026 Well I just - sort of saw my writing - actually - and it looked
- a sort of barrier actually [presumably referring to his description
of the test which "divided" the page] to the question - so I just
didn't see that — so - ah - chlorine is an oxidising agent - because
it er - it accepts an electron - er - so - itself is reduced - so it
is an - it brings about something else is - [agrees that he knew it
was an oxidising agent without the rationalisation] ..... [Agree to
omit 4 as this class has not covered the topic in question].
5. 026 [Reads aloud - repeats "neutral atoms" and has a silent look at
the table] - right oh -
5(a) 026 [Reads aloud] - so - number of electrons 6 - no - 18, 18 - so
it's M and Q - because they've got the same number of electrons and
so they've got the same number of protons - but the mass number .....
differs so it must be the neutrons - and difference in neutrons is
iso - is different isotopes - so put M and Q.
5(b) 026 [Reads aloud] - well this one - group er - they've got the same
and (c) on the outer shell - same numbers - so - tch - er I don't see - I
don't think I need that anyway but - 2, 4, the other ones 2, 7 -
that's probably the next question which is - the next one's 2, 8, 4 -
2, 8, 6 - yeah I think it's E and J - now when I went through that
- A264 -
1 saw - that one had one less electron than a full outer shell - so
that must be a halogen ..... so put that down - G.
5(d) 026 [Reads aloud] - well It's got - oh and - the outer shells of that
are 2, 8, 8, 1 - so that's probably In the first - that's - in the
first - er group and L - which is - 2, 8, 6 - so - we'll get - have
2 Xs to one L — because then - 2 X's will give one each to the L -
to form outer shell - complete outer shell so it'll be - X will come
first - because it seems like the metal - it's probably the metal -
and L - so it's - prob - X Lj
Ex Now - have you seen a question like this before?
026 Yes we - actually in er - class we did similar ones where we had
X and Ys - and P and Qs and things like that ..... [Ex encourages].
6(a) 026 [Reads aloud slowly] - well that was because they're solid
particles and they can be filtered and extracted in the process of
filtering - er [writes] - in filtering - the solid particles - can
be - extracted - er - now -
6(b) 026 [Reads aloud] - oh no - I should really have gone on in the one
above - perhaps gone on about - er - if not in excess - there would
have been an excess of a liquid which is harder to separate - because
really the next question - perhaps might hint that that should have
been my answer - er [rereads (b) aloud] - er - that's iron [writes].
6(c) 026 [Reads aloud] - oxidising agent is reduced itself - it is reduced
itself - and necessarily oxidises something else so - er - can I
perhaps write an equation?
Ex Yes .....
026 - right so - er copper sulphate - CuSO^ - I always remember that
- A265 -
one ..... er aqueous - plus - iron - er Fe - solid gives - FeSO^ -
plus Cu — so [sighs] — reduced is copper ion — reduced is a gain of
electrons so it s iron — oh no — sorry — reduced is copper because
it gains electrons — er — electrons from its ionic form which was
- plus - so that means it was - sort of - er had more protons than
electrons - so er - copper is reduced so iron is the - iron again -
is the oxidising agent - er -
6(d)(i) 026 [Reads aloud] — er FeSO^ — oh dear — that's ferrous — um — I
suppose it might decompose - I'm not sure - er - let's see - a
reddish-brown precipitate was formed and the mixture was filtered
- filtered um - the filtrate was evaporated - saturated solution was
formed - er - I don't really know this - [Ex explains that the
precaution is to exclude atmospheric oxygen and asks to attempt (ii)]
6(d)(ii) 026 [Reads aloud] — er so — got to sort of keep oxygen — away — er
- let's see - a practical way for a normal lab is this - so - it's
the oxygen - so perhaps it could be prepared - I don't know - in a
closed environment - or an environment where nothing comes in -
evaporated - how do you get rid of the water - er - perhaps we have
- er - going in we have a bell jar - we have air - minus oxygen -
perhaps we can get this by passing it through pyrogallol - er into
the chamber where you've got the reaction taking place - er which
is quite hard really - [Ex asks to pass on to next part].
6(e) 026 [Reads aloud] - well - er a saturated solution - it's cooled -
and it's going to deposit crystals up to the point where it's not
saturated - and so you're going to get the solution itself - I don't
know how soluble it is - then you're going to get the solution being
- A266
filtered off - and you*re going to have the crystals - dried but
the solution - will have been er — I suppose wasted — unless you take
in - er you’ve got to take it down in temperature — but - er - can
only go so far I suppose because — the whole thing’s going to freeze
up — but you’re going to have to lose some - because the crystals
that are deposited — are only deposited up to the point where the
- the solution isn't saturated -
Ex Fine — now you knew the right idea straight away — have you
answered a question like this before?
026 Er - no not really - don't think so - [Ex asks why he was able
to answer so easily] - I just remembered ? [unclear] so when we did
saturation - it doesn't get rid of all of it - just er - because
you're going to have - well we'll call it - a supersaturated solution,
at a higher temperature it has a - it has a capability to take more
- and as it cools that capability reduces - but it still has a
capability to take things into solution - ..... [writes] - ..... the
crystals are deposited as the - temperature - lowers - er - but the
remaining - liquid - is still - a solution of the compound - only
it's saturation point - point is lowered - with the drop in
temperature - so when filtering - the - er - mix - would you call
it a mixt - the - oh ? [unclear] the crystals - er - some of the
solution is wasted - wasted -
7- 026 [Reads aloud] - atomic level - well I don't think I've come across
that term - really - unless level refers to the different stages - or
the electrons - the different shells - so I'll probably assume that
and go on from there - well - oxidation - oxidation - is - the - er
- oxidation or reduction is gain so it's - is the loss of electrons
- I suppose here - I mention it occurs in the metals ..... [Ex stops
- A267 -
owing to shortage of time - 026 explains that he was going to try
to relate it to electron shells - the loss from the outer shell].
7(b) 026 [Reads aloud] - well really I'm never very quick on these so -
hydrogen is - losing an electron - which is - being oxidised so I'd
underline that [does so] - er yes - just check that 'cause I'm never
very sure with these - I have to think these out - so copper - and
bromine - er - copper again is losing - it's become more positively
charged - so I'Id say it was copper - again - oh being yes - being
oxidised - at first I thought it said been so that would have had to
- because in questions like this the phrasing can sometimes - .....
7(c) 026 [Reads aloud] - so from 4 to 6 - urn - [reads (ii) aloud] - oh
hang on - I might be - er sulphur - 0 ^ to - um - I think we did a
subject where we put - sulphur dioxide - er plus oxygen, plus 0 ^ ~
gave sulphur trioxide - so I presume that that's it so it's the
Contact Process ..... at first I was a bit misled by the way
sulphur(IV) - and then - when I thought that the oxygen - I thought
- but then it should be sulphur(VI) to suphur(V) - but then I suddenly
realised that if oxygen has a valency of 2 minus - so it did work
- so - and then the - nitrogen to ammonia - I'm not sure about this
- ? [unclear] - I remember the Haber process - but, I think that -
er I'd probably put that in an exam - because I haven't got anything
else - I can't remember anything else -
Ex The doubt in your mind is because of what?
026 Er well I can remember something - er - Faber - no that's not
one - but Haber - there's another process I thought might be Haber
- so I'm - or am I confusing it with the extraction of sulphur -
from the ground - Frashe - I'd probably put Haber - but there's some
-A268
doubt because I have'nt really learnt that too - [after some
discussion decides to try 9 as there is time for one more question
only].
9(a) 026 [Reads aloud - saying propane] - propene - so I'll put ethenes
- 'cause I can remember the endings are similar - propene -
9(b) 026 [Reads aloud] - so we've got - - oh - hang on - propane -
ethenes, ethanes, ethynes - er - ethane - I think ethenes have a
double bond - er - - so that - if you've got 1 carbon - and with
a double bond with another - I'm sort of experimenting [draws] - er
it's got two - er - then - that's got 2 bonds left so one could be
H the other carbon - er - now that's got 3 bo - no that's wrong
..... and then it's going to be - only you have 4 hydrogens to the
3 - so - I'd guess at - er it must be - a single bond between - so
it's carbon - hydrogen - oh yes hydrogen - carbon - hydrogen coming
from it so that's [has drawn Ct^-CHj-CI^-] no - unless - no - I was
thinking it could be a triple bond - but I think I - can remember
those are ethynes I think - so I'll just have to experiment again
- so - if I have another carbon - er - oh - er - oh yes - or no it
won't work - it's 4 isn't it - no - ethenes - must be - oh of course
sorry it is only a double bond but I forgot on one of the Cs on the
other side - to put 2 hydrogens [he had C = CH - CH^] - so - and then
there's a single bond to a carbon - er - one of the three hydrogens
- then there's a hydrogen off one - and two hydrogens off another -
Ex Right - how did you suddenly realise that - because you were
virtually there before and then you got sidetracked?
026 - Well I completely forgot about - the two spare bonds of that
carbon - of the - in that one ..... and er - I suddenly realised -
..... well I was pretty sure in my mind that ethene was a double bond
- A269 -
9(c)(1)
9(c)(11)
9(d)(1)
9(d)(H)
but when I saw It didn't work - well - only because of my fault
I suddenly th - tried another - ? [unclear] - and then it suddenly
clicked -
026 [Reads aloud] - gas I suppose - prop - oh no - propene - er -
probably guess at a plasticy - I don't know why but - [026 stuck here
so Ex gives answer for ethene as poly-ethene and passes on].
026 [Reads aloud] - dimer - oh it's er - oh we just mentioned it I
can remember because we did dimerism - of - of nitrogen er - nitrogen
dioxide to dinitrogen tetroxide - and I remember he mentioned this
about plastics - and it's - polymer - 'cause that was two - and this
is polymerism or - 'cause that was dimerising ..... I'd probably
put poly - merising - because I remember dimerising was two - and
in this case - .....
Ex What do you think polymerising is?
026 Well it's forming of a bond — between compounds — er — perhaps
similar compounds - to form a larger molecule - .....
026 [Reads aloud] - well that's a compound that contains only hydrogen
and carbon - er - atoms in its make up and -
026 [Reads aloud] - oh (c)(i) - polythene - well if that's the one I
named - oh no - it's propene -
Ex Well polypropene - it's very much the same thing.
026 Polypropene - yes - I would say so - yes - and er - what is -
a compound that [writing (d)(i)] er - contains only - er - hydrogen
~ and carbon atoms.
- A270 -
Ex Yes - could you explain why you said yes for (d)(ii) -
026 For (d)(ii) - well polypropene - propene itself would be - er -
just a carbonate - what you mur — call — it — a hydrocarbon — and
polypropene just seems like a big polymerised molecule - of the -
what that's ~ that itself I mean — it doesn't seem to have anything
else -
TAPE ENDS
- A271
PUPIL 027 ~ TRANSCRIBED PROTOCOL (TEST 03)1(a) 027 [Reads aloud] — so first I look at the ions involved - which is —
which are - H - S - S0^ 2 minus - H^O and OH will attract negative
ions - and er - sulphate ions are never given off so it'll be OH -
that'll be given off - and that - do I put the answer straight in?
..... and the - gas formed at the cathode - H O will be attracted -3
so it'll be H^O [writes in margin] plus one electron - will give you
- er there - er two H^O + H - plus hydrogen - and at the anode - it'll
be 2 OH - minus - minus 2 electrons - will give you - er - er H^O
- plus oxygen - so - er - at the anode - oxygen will be given off -
and at the cathode - hydrogen.
1 Ex Right now - if you were doing the actual exam and met this question
- would you go through all that reasoning - I wonder how much of that
was for my benefit?
027 I thought we had to think - well perhaps - you know if I was doing
it for an exam perhaps I'Id know it better - just write it straight
down you know. [Ex explains what he wants again and goes on] -
Ex ..... so - let's do that for these two - did you know as soon
as you read the question that it was oxygen at the anode - and
hydrogen at the cathode?
027 Yes - I think I did yes ....
^(b)(i) 027 [Reads aloud] - because - a 1:2 ratio's expected - because - the
- the ions accepted - shall I write it down?♦
Ex Yes
027 The ions - er - the ions accepted - well accepted at the -
accepted at the anode - are equal er - the ions accepted at the anode
- ? [unclear] change it now - the same number of ions accepted at
the anode are accepted at the cathode - I was going to phrase it wrong
- the same - same number of ions accepted at the anode are - accepted
- [writing] - at the cathode - so - er - the anode - is accepting -
Ex Could you explain what you're doing with the equations there?
027 I'm trying to - the equations I'd written down before - I did
them you know quick because I knew the answers - I was just trying
to do them properly - to see - which - because I don't remember the
experiment that well - trying to work out the answer - so - 2 OH -
minus 2 electrons - gives you - 2H - H„0 - plus 0 - and 2 H^O plus 2
electrons - gives - 2 H^O - so it'Id be yes [writes H^] - ..... same
number ions accepted at the anode are accepted at the cathode -
therefore - therefore - one - therefore one molecule - of oxygen -
is given off - is given off - with - two molecules of hydrogen - [027
agrees he would probably put the equation with the answer in an exam].
l(b)(ii) 027 [Reads aloud] - er - because - because er - er - .... because
the oxygen - because the oxygen is dissolved - so I think - I don't
remember the experiment all that well so I think - er - more hydrogen
is given off - than 2:1 - because some of the oxygen dissolves.
E x ..... how did you think of it?
027 Well I remember that - that one of them was dissolved - and I
was trying to think of the experiment when we did it - which was about
2 years ago - so as - [Ex discusses and encourages].
1(c)(i) 027 [Reads aloud] - er - increasing the concentration of the sulphuric
acid - urn - so I'm thinking - I'm looking at the ions involved - and
seeing - so the S0^ is not given off at all - the - hydroxide ion
- which is in the water - is given off for the oxygen - the
hydroxonium ion - is given off for the hydrogen - and there's also
- er - ion - coming from the dilute acid so I'Id say that - it would
- it would - decrease the amount of oxygen given off - and - perhaps
it would decrease - the amount of both gases given off - but more
so the oxygen — shall I write that down? — [Ex asks 027 to carry on
A273
unaided from now on] - the - the volume - the volume of the gases
given off - would - don't know - suppose they would increase -
Ex Now I thought you were saying earlier that they'Id decrease?
027 Yes but it just doesn't seem right - so even though I think that
in an exam I'Id still say increase - ..... because - from my thinking
it'Id decrease - especially the oxygen - but - when I think - when
you've got a stronger - er more concentrated electrolyte - I think
the gases would increase ..... - not that I know the reason - .....
l(c)(ii) 027 [Reads aloud] - er - increasing the temperature - well that would
- how would that affect - the ions - er - er - make - er - perhaps
the ions - the gases would be given - would be - would be given off
more rapidly - because the ions would be moving faster - inside the
solution - so they'Id bump into the - electrodes - more quickly - and
that's what - my theory would be - gases would be given off - more
rapidly [has written as he went along].
1(d) 0 2 ]_ [Reads aloud] - well - in dilute sulphuric acid [repeats this
as he writes] - electricity is conducted - by - the ions - whereas
- in a copper wire - electricity - is conducted - by - free electrons
- in the wire. [Ex asks how he got this answer] ..... oh I just
knew that - well - you know I like electricity so ..... I just knew
that instantly ..... I think we'd perhaps - we'd done this - with
an - ionic solution compared to covalent - where there's ions and
they conduct electricity - and that's - stuck in my mind - more -
than just electrolysis - and we've done this more recently as well
2(a) 027 [Reads aloud] - so I'ld write NH^ - C03 down - then think that -
the valency of NH^ is one - the valency of C0^ is two - and by cross
-
- A27A
method 1' Id make that NH two and CO one — so NH brackets two — CO4 3 4 3
- [027 explains that he just memorises valencies and that he puts
valencies "over the top" and then crosses them over].
2(b)(i) 027 [Reads aloud; re-reads aloud] - er - I'm thinking about indicators
- so I know that water - turns - er - anhydrous copper sulphate -
which is white - turns it blue but that could be any substance
containing water so I'Id also have to test - er - the boiling points
- and the melting points - I mean the boiling point and the - freezing
point - so - I would - I would boil the liquid [writing] - boil the
liquid - and - and compare the boiling point ..... to 100°C - which
is the boiling point of water ..... then - I would - I would cool
it - and - see whether - it solidified - at - 0°C - which is - the
freezing point of water - point of water.
2(b)(ii) 027 [Reads aloud] - yes well - structural formula - er ah - it will
have - er - m - ammon - er NH - two - CO - er - so if I - 2 NH s and2 2
one CO - well ? [unclear] I'm not sure - structural formula - I think
- there will be - one CO - what if you don't know the question? -
..... I'Id leave it and go back to it at the end - I'Id go through -
[Ex encourages to have a bit more of a try first] - so CO -
Ex You've written down just CO.
027 Yes - because - and there'll be 2 NH^s - er - that will be - I'm
thinking - what - what structure it will take - so - er - I - I'11
put that -
Ex You've put an NH^ group each side.
027 I'm afraid it's just a guess - .... rather than leave it out.
3(a) 027 [Reads aloud - reading manganese(IV) oxide as manganese dioxide]
- er - I'm going to - I'Id just - write down - plus HC1 - and this
- A275 -
gives manganese chloride - plus - [Ex queries what is being written]
- ..... I've written - I think - manganese - Mn - Mn^O^ - plus HC1 -
will give er - manganese chloride - I was - no - I don't really know
the equation so I'm trying to think - when we did the experiment -
and I think it was - we were doing it for - chlorine - because - I'm
thinking of another equation now to get HC1 - what you do - (with?) -
H^SO^ - so I'm - thinking back at my exercise book - which I haven't
looked at for some time - and I think the gas is chlorine - but there
again - if I'Id tried to do the equation - ..... I'Id do -
manganese(IV) oxide - er and I'd say - is that manganese dioxide
'cause I've never heard of Mn 0 - just put MnO - plus HC1 - reacts2 4 2to give - er - I'Id say - manganese - chloride - plus - plus water
- so that's 2 HC1 - and that would give me - if my theory is right
there'll be a Cl^ as well - so - ? [unclear] 2 H^O - 'll give - 4
HC1 - that'll give 2 Os and - now - so one Mn, two Os, four Hs and
4 Cl - so ? [unclear] - I'ld say it was MnCl^ as well so I'ld say
chlorine was given off - the name of gas - chlorine [writes] - .....
chemical test - now I'll have to - think back - greenish yellow gas
- didn't like the smell much - test - oh the test for - or - ?
[unclear] the test for chloride ion but no - chlorine - er - there's
a - of lead ions - lead chloride - oh I'ld leave that to the end and
go back .....
3(b) 027 [Reads aloud] - so - I would - yes - ? [unclear] dilute sulphuric
- dilute hydrochloric acid - HC1 - which gives - er - ferrous -
ferrous chloride - plus H - and there's an H and an S - left over - so
H plus “ hydrogen sulphi “ H 2 S “ I think of — so now see if I can
make them balance - which - side would have 2 HCls - and that's
balanced — so — hydrogen sulphide - I'ld put down [does so]«
Ex Now you've worked it out do you recognise that as being right -
are you sure or -
- A276 -
027 I'm not positively sure no [refers to lack of revision etc
and that this is particularly necessary in a subject like chemistry
- on lead ions - which gives a black precipitate of lead sulphide
- so that's what I'll put down - when - lead ions - are added ...
3(c) 027 [Reads aloud] - so er - I'll just do another little equation -
- plus - plus - ammonium hydroxide - er - ammonium hydroxide - but
- now - we had two hydroxides - that's - no - we had two hydroxides
- that'Id make two - two there - ammonium hydroxides - I know that
- ammonium chloride - I know there's one that - it sublimes - I think
- yes - ammonium chloride sublimes - so then - I would give off -
hydrogen chloride and ammonia - and - but the calcium hydroxide -
I'm not sure what that could be there for - calcium hydroxide - er
- no -
Ex What sort of substance is calcium hydroxide - how would you
classify it?
027 - a base - or -
Ex Yes - a base is right.
027 - or - a drying agent perhaps I was thinking of - ..... an acid
would be given off - HC1 - gas - hydrogen chloride gas - so - but -
I was thinking about reacting with a base but that just gives salt
plus water - and I know that ammonia's given off as well - and - but
then ammonia with calcium hydroxide - er NHj + Ca(0 H ) 2 - would give
off - er - I'm not really sure - [Ex discusses correct answer to
enable 027 to try other parts].
which he doesn't enjoy] chemical test - I think that's - yes
to the gas a black - precipitate - of lead sulphide - is
formed
- A277
4(d) 027 [Reads aloud] - which of these gases - er chlorine - hydrogensulphide - and ammonia - I would say it's chlorine - and I'Id - just
to make sure - Cl - the chlorine ion is Cl - that means it gains
an electron - and oxidation is the loss of electrons - so it would
be an oxidising agent and sort of gain electrons so I'll put chlorine
down - chlorine - [agree to omit item 4].
5(a) 027 [Reads aloud - re-reading the first part] - er so - isotopes -
they will have the same number of electrons but different mass numbers
- so - I look for the ones with the same number of electrons - M and
- is that 0 or Q - ..... M and Q - and they have different mass
numbers so I'll say M and Q - and M and Q [writes].
5(b) 027 [Reads aloud] - to be in the same group they need the same number
of electrons in the outer shell - so - I'll just work out - let's
see - E - has 4 electrons on the outer shell - G - has 7 - J - has -
4 - L has - 6 M - has 8, Q has 8 - and X has - er one [writes these
numbers above table] - so I'Id say that — E and J — E and — J [writes]
- just to make sure - yes E and J .
5(c) 027 [Reads aloud] - a halogen has 7 electrons in the outer shell -
and I've just worked them out - G -
Ex How do you remember that a halogen has seven?
027 Oh - I just learnt that - .....
5(d) 027 [Reads aloud] - so I've worked out that X - has 1 electron in the
outer shell — just to check again — 8 + 2 is 10 plus 8 is 18 yes - L
- I've worked out that has 6 - electrons on the outer shell - just to
check - 8 + 2's 10 yes - so - X must have a valency of 1 and L must
have a valency of 2 - because it needs 2 more electrons to make an
outer shell so — 1' Id write down XL and use my — my crossing over
- so 1 - and L has 2 — so it's X^L — just to make sure — yes [Ex
encourages].
6(a) 027 [Reads aloud] - so now I just go back to the question where it
says that and see - so crystals of iron(II) sulphate were prepared
as follows - an excess of iron filings was added, a little at a time
with stirring, to a solution of copper sulphate in water - so I'Id
think that - an excess of iron filings was used - so that - all -
all of the copper sulphate - would be used up — and the excess of
iron filings could be easily filtered away - whereas the copper
sulphate couldn't - so I'Id say - [writes] because - er - to a
solution - because no - unused - well unreacted - unreacted copper
sulphate - copper sulphate would remain - would remain - and - iron
filings - filings - are easy to filter off - are easy - to filter
- to filter.
6(b) 027 [Reads aloud] - iron filings - oh wait - a reddish-brown
precipitate was formed and the mixture was filtered - the filtrate
- was evaporated - so - at this stage I think I would see what the
reddish-brown precipitate - I'Id name the reddish-brown precipitate
- iron sulphate was prepared by copper sulphate plus iron - so - er
- iron(II) sulphate - is usually brown - so that is iron sulphate
- I'll write iron sulphate on top [does so over the words
"reddish-brown precipitate"] - so the iron sulphate was formed and
the mixture was filtered - the filtrate was evaporated - so I'll read
the question - give the name of the substance which had to be filtered
off before crystalising the solution - the filtrate was evaporated,
taking all necessary precautions, until a saturated solution was
formed - the solution was then cooled and the crystals were filtered
off and dried - yes - 7 [unclear] - iron filings.
- A279 -
6(c) 027 [Reads aloud] er oxidation — is a loss of electrons so - anoxidising agent gains electrons and - iron was used Fe plus CuSO - so
4forms [writing equation] FeSC>4 plus Cu - and Fe 2+ - SC>4 2 - minus -
so - the — er — the iron doesn't gain electrons — so — the copper
- the copper sulphate gains electrons - the copper gained electrons
- which of the substances used acted as an oxidising agent — the
copper sulphate -
Ex You say that because copper gained electrons.
027 Yes - because I know that oxidation is a loss of electrons so
an oxidising agent must gain electrons - and also - I've just
remembered from the chlorine - from the question before — copper
sulphate [writes].
6(d) 027 [Reads aloud then re-reads again slowly] - so iron sulphate -
while it was er - evaporated - to obtain a reasonably pure product
- what do you think this precaution might be - iron sulphate - er
- I'm thinking - if I can remember what iron sulphate - is - er -
any of its special properties - so - well I'Id leave that and go back
to it and go on to (e).
6(e) 027 [Reads aloud] - [Ex assures that part (d) is unrelated to this]
- oh yes - so - [re-reads question aloud slowly] - 1'ld go back to
the question - the filtrate was evaporated taking all necessary
precautions - until a saturated solution was formed - the solution
was then cooled - and the crystals were filtered off - and dried -
so - it says that - as the mixture was filtered - a reddish-brown
precipitate was formed - and the mixture was filtered - the filtrate
- was evaporated - oh - now I see where I've gone wrong in the
question - 'cause I hadn't read it well - so the reddish-brown
precipitate - that was formed - was copper - ..... so I've got me
- A280 -
equation there - I - I read through the question - too quick and never
really understood it too well - so I put copper down - was formed
and the mixture was filtered - so - give the name of the substance
- so I'Id go back to the other question (c) - have I got it right
- [re-reads (c) aloud] - so a reddish-brown precipitate was formed
and the mixture was filtered — so — it was the copper and not the
iton filings [Ex chips in unnecessarily and 027 agrees that the excess
iron filings would remain as well as the copper] - ..... which of
the substances used acted as an oxidising agent — copper sulphate
- yes — I'll go back to — now I'll go back to question (e) — ?
[unclear] the mixture was filtered — the filtate was evaporated taking
all necessary precautions - until a saturated solution was formed
- the solution was then cooled and the crystals were filtered off
- and dried — [re-reads (e) aloud] — because — the crystals were
filtered off - so some of the filtrate - er - did not actually - er
- crystalise -
Ex Right again - spot on - but again, how did that idea occur to
you? - because that question has given a lot of difficulty - .....
027 Yes - well it occurred to me because - I knew that - well I had
a feeling that the answer - I hadn't read the question well - so I
was thinking - the answer must be in the question somewhere - so I
went through it slower - I'Id already been through it a few times
because - long questions - I don't take them in straight away - I
was going through again - the filtrate was evaporated taking all
necessary precautions - until a saturated solution was formed - and
then I read - the solution was then cooled and crystals were filtered
off and dried - so when I say filtered off - it just clicked - .....
shall I write that down - ..... [re-reads (e) aloud yet again] -
there is a difference [repeats] - difference because - some - of the
filtrate - filtrate - was - was - poured - poured away - and - ?
- A281
[unclear] some of the filtrates did not crystalise - [repeats] -
crystalise - and was — and was poured away - [wants to return to (d)
but Ex asks to go on to 7 owing to shortage of time] - ......
7(a) 027 [Reads aloud] - changes at the atomic level - think - what does
changes at the atomic level mean ? [unclear] - er - so - oxidation
is a loss of electrons - I'Id say - oxidation - oxidation - is a loss
of electrons [writing] - is a loss - of - electrons - or - or a
gaining of hydrogen - or a gaining - of hydrogen -
7(b) 027 [Reads aloud] — er — oxidation is — loss of electrons “ so the
Fe - so the H - the hydrogen is positive - and the ? [unclear] - so
that means it has - lost an electron - so the iron is being oxidised
- and anyhow I know that metals - I think metals are oxidising
agents so - underline the substance which is being oxidised - and
also - the copper - the copper has lost electrons - in the second
one - because it has - 2 positive - so -
Ex So you've underlined which in the first one?
027 Hydrogen and the copper.
7(c)(i) 027 [Reads aloud] - er - sulphur(VI) oxide to sulphur - (VI) - er
- catalytic oxidation - I'll just go on to the next one - the
catalytic reduction of nitrogen - to ammonia - I know there's a Haber
process the Ost - wald process - I was trying to think - which fits
in - ammonia - for part (i) I'm not sure - for part (ii) I'Id put the
Haber process - well I'm not sure on any of it -
Ex But you'Id put the Haber process because you - ?
027 Because I remember I learn't it - er - for the - for an exam'
- and remember it - with ammonia - I'm not sure of this - but I think
Haber - Haber - with the ah of ammonia - I sort of fitted them
- A282 -
together - I might be wrong - I'm not sure if it's right - but I'll
just have a guess - ..... I know that there's an Ostwald process
as well - but - I don't think it's that - [Ex directs 027 back to
part (i) and suggests translating the names to more familiar ones
or to formulae] - ..... er - well sulphur(VI) oxide's completely
puzzled me - I never - er -
Ex Well, what must the formula be?
027 Sulphur(IV) oxide - usualy - either - sulphur dioxide - well that
must be - sulphur - er - S - SO^ SO^ - sulphur 6 - that could be SO^ -
..... and sulphur(IV) oxide SO - ..... SO to S0„ - er - is that2 2 3in the - sulphuric acid - is that Ostwald process - perhaps I'll put -
? [unclear] - SO^ er - ? [unclear] - I'Id perhaps have a guess and put
the Ostwald process - [goes on again about not having revised]. [Ex
offers choice of 8 or 9 - skims both reading aloud and opts for 8].
8(a) 027 [Reads aloud] - I'll put sodium stearate.
Ex You just know that?
027 Yes - .....
8(b) 027 [Reads aloud] - now - I think - er - sodium stearate [interrupted
by arrival of next pupil] - ..... e r - I'm trying ? [unclear] to
think of things that cuase the hardness of water - because - er - not
really sure -
TAPE ENDS
- A283 -
PUPIL 028 - TRANSCRIBED PROTOCOL (TEST 03)
l(a)(i) 028 [Reads aloud] - that'll be - the oxygen won't it so - shall I
fill it in?
Ex Yes please - ..... you just knew this?
028 Well - I sort of knew it because - when I was in - the third form
- I got it wrong - and so Mr ? [unclear] explained it to me - and
I've remembered it from that rather than working it out - ..... well
really. I don't really know how to work it out - from - ..... I
shall write oxygen.
Ex The bit of a pause there - were you trying to remember - which
way round the two gases were - or what?
028 Well yes - but er - I think it's more trying to think back over
what happened - rather than - actually remembering what we did -
l(a)(ii) 028 [Reads aloud] - it'll be hydrogen won't it - there again it's
from memory now - [writes].
1 (b)(i) 028 [Reads quietly but quickly] - er well - because the water contains
them sort of - in those proportions - [mutters; writes] - the water
contains the - it's 2 - [Ex asks to speak up] - why is the 1:2 ratio
expected - because the water contains - er - hang on - I've written
it down funny haven't I - because the water contains - urn - er - 2
parts [writing] - to 1 - oxygen [Ex asks why water when question is
about dilute H^SO^] - ..... sorry - the SO^ - radicle's not
discharged - because it's below the - er - hydrogen is it - no below
the - in the table - sort - of - electropositivity is it - it's lower
down - and so it's less likely to be discharged - er - [Ex agrees
but asks if this was really how he knew it was electrolysis of water
- A284 -
or if it was simply memory] - .... well really most of what - the
that chemistry I do is from memory - because - I suppose it's because
of an early interest - and 1 read more about it - and found that most
of it's what I do from memory - [agrees that he realised it was
electroysis of water as soon as he read the question] -
l(b)(ii) 028 [Reads aloud] - well - I suppose - being as oxygen's more soluble
than hydrogen - I suppose some of the oxygen will dissolve [writes]
- of the oxygen - will - dissolve - in the solution - in the
electrolyte [Ex asks how he got there] - no I could remember that
oxygen - dissolves in water - because the things like fish life and
things like that - I couldn't really think whether hydrogen did or
not but I didn't really think it did - [Ex establishes that he does
not recall answering a similar question before].
l(c)(i) 028 [Reads aloud] - ah - can't remember that - ...... well it would
increase the number of ions - er in the solution - so I should think
it would - make it go faster - .... [re-reads item aloud] - er -
well it would be more ions — so — that it would — come off faster
[writes] - the - gases - would -be evolved - greater - rate.
l(c)(ii) 028 [Reads aloud] - well - the ions would move about faster wouldn't
they — so — again - it should go faster [writes] — the gases would
be evolved faster.
1(d) 028 [Reads aloud] - oh well - in copper wire the electrons are like
a cloud and they — sort of go along - they're not particularly
attached to their own copper atom — where — as — in the sulphuric
acid there's - ions which carry the electricity - ? [unclear] so -
[writes] - copper - electrons - are - not attached - to - their - own
atom [reads back aloud] - so - no - er - in - dilute - sulphuric -
aci8 - ..... the electricty - no the electrons - the electricity
is transferred - through er via - via - the ions - [Ex asks how he
got the answer] —
028 “ oh well “ not very long ago really we - said that - we did the
topic of metals — and we said that in — in a metal the — atom — the
sort of atoms are sort of - all stuck together - and the - but the
electrons go round in a cloud — round the metal — so I could remember
that bit and I could remember that the whole lot of the electrons
moved along — but — in then — er — case of the dilute sulphuric acid
I couldn't really remember - apart from that the ions were moving
about - I just said that they'Id carry - I said that they'Id carry
- the electrons from one to the other - .....
2(a) 028 [Reads aloud] - well - ammonium - 's got a valency of 1 hasn't
it - so it's NH^ - two times - 'cause carbonates got a valency of
2 - 2 times - CO^-
Ex And how do you remember the valencies?
028 I've learn't them - ..... I didn't have a real way - I just
learnt the valencies er -
2(b)(i) 028 [Reads aloud] - er - well - it would be - you could do it by
cobalt chloride - 'cause it will replace the water of crystalisation
- whereas the urea wouldn't - er - [mutter] — but you'Id have to
dry the ammonium carbonate first - so - with the cobalt chloride
[writes] cobalt - chloride - would turn - from - blue - er anhydrous
cobalt chloride - anhydrous cobalt chloride paper would turn from
- A286
blue to red - if - water - was - present - but - the ammonium -
chloride - no carbonate - would - have - to be - dry - first - right.
2(b)(ii) 028 [Reads aloud] - NH2 -
Ex How are you trying to tackle this?
028 Well - I don't really know - I never come across anything like
that before - so - ..... I'm just trying to think - so - can I draw
it in pen - ..... er - well - nitrogen's got a - valency - of 3 -
but it comes out in a paramid - looks like a paramid so - er -
nitrogen - [drawing] - and then -
Ex So you've written down N - .....
028 N - so a H coming off - 2 H's coming off - H - H er - CO - now
CO - ? [unclear] [whispers] - plus NH2 - try another one over here
- CO - N - and - H - H right - CO - would it be double bond - er -
CO - it'll have a single bond won't it - I think - yes - right
- I think that's it - ? [unclear].
3(a) 028 [Reads aloud] - ah - so the hydrochloric acid would be - oxidised
wouldn't it - or is it reduced - so I'Id get chlorine coming off
wouldn't I - I think - or would I - yes - I think - so [writes] -
chlorine - er bleaches - damp - litmus.
Ex Now you read manganese(IV) oxide as manganese dioxide — was that
deliberate? -
025 Well I thought when - er - the - we had an old textbook - and
it always it called it manganese dioxide and I've just stuck to it
3(b) 028 [Reads aloud] - now ferrous sulphide - it'll be hydrogen sulphide
— yes - er — so you get iron chloride - ferrous chloride - so —
sulphur - hydrogen sulphide [writes] - [028 agrees this is just
memory and that he was trying the equation in his mind to confirm
that it would actually work] - ..... what's the test - er lead -
lead ions or something - I think it's lead sulphide therefore - lead
[writes] - lead - nitrate - paper — if you use lead nitrate paper and
will — turn — black — er — with — the — lead ~ sulphide ~
formed - right er.
3(c) 028 [Reads aloud] - get ammonia don't you - ammonium chloride -
calcium hydroxide - calcium chloride - yes - 'cause it's - er any
ammonium compound plus any base - gives ammonia - so - name of gas
ammonia - [writes] - chemical test - er - well it's the only one that
turns — litmus paper blue — or red — blue — er chemical test [writes]
- turns - litmus paper - turns red litmus - paper - blue -
3(d) 028 [Reads aloud] - oh dear - what's an oxidising agent - chlorine
isn't it - because - I can't really think of a reason.
Ex During that pause you were looking at all three were you?
028 Yes - I was just trying to see - what we'd got - because - you
know - I couldn't remember - so - won't be hydrogen sulphide - or
ammonia - it'll be chlorine.
Ex Why wouldn't it be hydrogen sulphide or ammonia?
028 Oh sory - well I can remember that - chlorine - is quite a good
oxidising agent - from it turning - you react it with iron - you get
ferric chloride - and - well - ..... I couldn't think of anything
that they oxidised - or reduced or anything - so really I suppose
it was a guess - [Ex instructs 028 to omit item 4].
5(a) 028 [Reads aloud - studying table quite thoroughly element by element]
- well isotopes have got the same number of protons haven't they -
so - 6, 9, 14, 16, 18, 18 - it will be M and Q - M and Q [writes]
- M and Q - er -
- A288
5(b) 028 [Reads aloud] - it's a matter of the same valency - er - got the
same number in the outer shell - ? [unclear] [whispers] - 6 -
Ex Say what you're doing.
028 Oh sorry - er - right - yes - .... well - forgot the question
now [re-reads aloud] - same group - same valency so - 6, 9, 1 4 - 1
want 8 difference don't I so - 1 4 - 8 - 9 - and 19 ? [unclear] so
- it won't be 6 and 14 [has gone to a very quiet whisper again] -
urn - 18 - urn - can't think of any in that - ? [unclear] C' - er - 2
- 2 in the inner - that's - 2 - 2 and 4 - and there's oh - 2 and -
for G there's 2 and 7 [writes configurations above table] - for J -
there'll be - 2, 8 - and 4, 2, 8, 4 - 2, 8, 4 so it'll be E and J -
they've both got 4 - in the outer shell - E and J -.......
5(c) 028 [Reads aloud] - chlorine - because it's got ions - no - er -
Ex Now again - can you tell me what you're trying to think.
028 Yes - sorry - I'm just trying to remember what the elements are
- oh - er - I'm trying to think of the periodic table - I can't
remember - urn -
Ex I thought you named one of the halogens just now.
028 Oh - chlorine - but - I can't remember whether it's got 1 7 - 1
think it's 17 - the atomic number's 17 er - um - try ? [unclear]
- 'cuase it's the only one I can really remember - M - do I put down
M and Q or M -
Ex You're doing it.
028 Oh - M and Q [writes] - right.
5(d) 028 [Reads aloud] - X - reacts with L - so er - X - and L - so the
structures are -2, 5 - 2 , 8, 6 - 1 think and -2, 8 - 2 - 2 , 8 -
2, 8 - 18 and 3 - oh no - yes - er so far L the structures 2, 8, 6
and for Xit's 2, 8, 8, 1 - so - 6 therefore X - 2 of X to one of L -
- A289
Ex Why?
018 Oh sorry - er X wants to give away one electron because it's got
one in the outer shell - and L's got 6 in the outer shell so it wants
to make a full outer shell of 8 - so that it'll want 2 - so - only
- X can give 1 - just 1 atom of X can give 1 - so you want 2 atoms
of X - so it's - X^L - [writes] X2L.
6(a) 028 [Reads - slowly with pauses] - ah - if copper's deposited - so
if you've got extra iron and you filter it off - if you don't put
enough in - you'll get copper sulphate with them - so - er - to get
to - to obtain [writing].
Ex - ..... you've come across similar cases before have you?
028 Well X just thought - that iron - the iron going in would be a
solid - and - er the - copper which would be deposited - because
iron's higher up - in the - reactivcity table - er I thought well
- if the iron - the copper - be deposited - you didn't want - you
didn't want the copper - you don't want the excess iron - but you
don't want copper sulphate contaminating the solution - so if you
put extra iron in you'll use up all the copper sulphate - [on further
questioning 028 is obviously unaware of referring back to a similar
example] - ..... [continues writing] to obtain a pure solution -
of - er - FeSO^ - to obtain a pure solution - not contaminated - not
contaminated with - copper sulphate -
6(b) 028 [Reads aloud] - be copper - it's copper - yes copper [writes].
6(c) 028 [Reads aloud] - so - actual substance would be reduced - therefore
it's gained electrons - um - iron no - the copper sulphate because
it's the only other one there - er - copper sulphate - [writes] -
- A290 -
6(d) 028 [Reads aloud] -
Ex Now - how are you setting about it?
028 Well - I'm just trying to read it again because I can't think
of anything that springs to mind immediately — because of the nature
[re-reads (d) aloud] - er - can't think of anything - peculiar about
ferrous sulphate - erm - 's the nature - oh - something to do with
the water of crystalisation - ? [unclear] - oh no - no I can't do
that one - I can't think of anything to that one at all.
[Ex offers a hint - sugesting that FeSO^ solution will start to go
brown as it is boiled]
028 Oh -er - ferric - ferric - ..... oh so - er - you don't want
- really - you don't want - the ferric sulphate in - so - if you
heated it more gently - you might still get it mightn't you - s o -
so - no - I'm still not much better off - apart from -
Ex But what sort of process is it that's involved - .....
028 Oh -
Ex - in forming the ferric - and what's responsible for that process?
028 ? [unclear] - still not much better off - [decides to go on to
(e); Ex explains that this is not related to (d)].
6(e) 028 [Reads aloud] - what's the question again - was the - oh I know
it yes - because - well - all the - ferric - ferrous sulphate - wasn't
- er - taken out of the solution -because it doesn't say that it was
- it says that it was only cooled - it doesn't say that it was
evaporated to dryness — so that some would be left in the solution.
Ex - how did you hit on that reason?
028 Well I just thought if - if you're going to still leave some of
the solution - if you're going to heat it up you'll evaporate most
of the water. [Ex agrees but asks about the generation of this answer]
- 291
- ..... well - if you took every care so you wouldn't lose it -
it wouldn't be deposited - with the iron - 'cause it's soluble - and
er - so - er - it must be in the solution - somewhere or other - so if
- you've just going to - sort of - not evaporate it to dryness you
must have left some in - that's the only - ..... oh I forgot to write
it down - ..... because - ...... some of the er - ferrous - because
ferrous sulphate was left in — as - it - was - not evaporated - to
- drynes [re-reads answer to himself under his breath] - so - that'll
do.
7(a) 028 [Reads aloud] - er I'm not really sure what it means - I don't
see what it means by changes at the atomic level - so - all I can
really think of is - it's the - loss of electrons is it - I think
it's the loss of electrons - I think that's a reasonable answer -
urn - [writes] - ..... it's the loss of electrons - I hope that's
right.
7(b) 028 [Reads aloud] - er - hydrogen's a good reducing agent isn't it
— so reducing agents are oxidised — so it'll be — hydrogen — er —
no - ..... I was just trying to think - iron(III) and iron(II) - er -
one of the tests for - an oxidising - or is it a reducing agent - is
converting iron(III) to iron(II) - I can't remember which way round it
is - I think it must be hydrogen - ? [unclear] - it is - it is losing
electrons - right er - number (ii) - copper and bromine - no - the
halogens are good - oxidising agents - therefore they're reduced -
so the copper must be oxidised — um —
7(c)(1) 028 [Reads aloud] - er - making - er name the industrial processes
used in the following - is sulphur(IV) oxide sulphur dioxide - it
- A292 -
is isn't it - yes - to - sulphur(VI) - it'll be sulphur trioxide -
sulphuric acid - [writes] -
Ex What have you written there?
028 Oh - making sulphuric acid er -
7(c)(ii) 028 [Reads aloud] - ah - catalytic reduction - nitrogen to ammonia
- ah - um can't really think of any - nitrogen to ammonia - all I
can think of's making of the - things like fertilisers - so that they
use the - ammonia - to get things like ammonium sulphate as a
fertiliser - um - oh - wait a minute -
Ex What are you doing now?
028 I was just trying to think whether it wants - a name like the
- things like - who invented it — called after the - er - or - sort
of - oh - that's all I can think of - I can't think of any of the
name - so - .... all I can think of is making fertilisers for
part(ii) [writes] - so -
8(a) 028 [Reads aloud] - sodium stearate - I can only do that by
remembering it - er [writes] - sodium stearate - .....
8(b) 028 [Reads aloud] - because [writes] - explain why soap will not
lather well with hard water - because some - of - the - sodium -
stearate - [028 explains this is a question he has answered recently]
- I just remember it - ..... explain why soap will not lather well
in hard water - because - some of the sodium stearate is used - to
remove - the - the calcium ions - and which er - which make the water
hard - ? [unclear] - a scum - a - scum is formed - which - because
some of the sodium stearate is used to remove - calcium ions which
make the water hard — scum is formed — holds back lather — ? [unclear]
- and - there - is - less - active sodium - left to make - the -
lather - huh -
8(c) 028 [Reads aloud - using sodium bicarbonate as name] - ah - um -
..... it's - all 1 can think of is - for the same weight - it will
give off more - carbon dioxide - but - there's not very much in it
- so I don't really think that would do.
Ex Which one would give off more?
028 - er the sodium bicarbonate - um - so - describe a chemical test
you might use to distinguish between sodium bicarbonate and hydrated
sodium carbonate — oh I know - you could heat the - you could heat
both of them - and - with one of them - carbon dioxide would come
off - and - the other just water'll - carbon dioxide and water'll
come off - but the other one just er - water'Id come off.
Ex Yes - now before you said they'Id give different amounts of carbon
dioxide if you heated them - why have you changed? - ....
028 Well I thought if you did that you'Id have to be so accurate to
- sort of measure it.
Ex Yes - but now you're saying one of them won't give any carbon
dioxide at all -
028 Sorry - before I meant if you added something like an acid.
Ex Oh - I see -
028 - ..... [re-reads question again and writes] - on heating - er
- the sodium - bicarbonate - [repeats] - would give off - erm -
[repeats again] - carbon dioxide - carbon - dioxide - ..... and
water - the sodium - carbonate - would - only give off - its water
- of crystalisation - and - no - carbon dioxide.
9(a) 028 [Reads aloud - saying propane] - propene - er - C ^ - less two
isn't it - so - oh no it isn't - it's CnH2 n ” so alkenes, alkanes,
alkynes - I can't remember them - alkene - let me think - alkane
- let's see - C H„ , - alkene and alkyne - huh - cant't remember
- A294 -
which is which - never could - it'll be - alkenes won't it - or will
9(c)(ii)
9(b)
9(c)(1)
9(c)(ii)
it - er - yes I think so - alkene - alkanes - C H, ,„ - alkenes -n Zn+Zalkynes - urn -no - I'll stick to alkenes [writes] -
028 [Reads aloud] - [mutters - but mistake has to be pointed out by
Ex - he had filled in previous answer at (c)(i)] -
028 [Reads aloud] - er that's - C - with a double bond - C - C -
that's three Cs with double bonds between them - and then an H off
each - H - 2 Hs off each - H - H - H - H - right - I'll go back to
(c)(i) now
028 [Reads aloud] - oh - propylene - polypropylene [writes] - it's
one of the poly - ? [unclear] I should think - 'cause that's the only
thing - that's really the only thing I can think of - so - can't be
polypropene — um — think of a plastic -
Ex You mentioned propylene — which series is that a member of?
028 I don't know - I can't remember - we haven't really done it -
it's just the - er - ending and really the beginning 'cause it's the -
Ex Well in fact propene and propylene are the same thing - .....
propylene is the old name for propene.
028 Oh - I see - so it's the same thing - so it's polypropylene isn't
it - ..... it's just - we've done - we've only - I only really heard
about these propenes. When we were doing chemistry — er — and I ve
heard of polypropylene — but I haven't really linked the two — we
haven't had any — so I don't think ? [unclear] — polypropene -
[writes] - right.
028 [Reads aloud] oh dear -
Ex Oh dear means that you know that you don't know?
- A295
028 Well - sort of - I know that the polypropene - polypropylene -
is like a long molecule - they're all - sort of stuck together so
you get these great big molecules - and - but - what name is given
to the type of reaction - used to obtain this product from propene
- er - can't think what it's called - it's sort of sticking together
of lots of propene - ..... but I don't - I can't think of the word -
Ex OK - try (d) -
028 I'll try (d) - see what happens.
9(d)(1) 028 [Reads aloud] - something er - a substance - [writes] - what is
a hydrocarbon - a substance made - made - of - hydrogen - and - carbon
- only -
9(d)(ii) 028 [Reads aloud] - yes - I think so.
Ex Why do you think so?
028 Well - when you make polypropylene - polypropene - you sort of
stick lots of propenes together - and I don't - I can't think that
you add - anything - to make them - sort of - into anything else -
so I'll put yes -
Ex OK - any thoughts on (c)(ii) yet - the name of the process?
028 No - I can't remember - I can't really - [Ex explains
polymerisation which 028 has not apparently heard of, although he
agrees he knows of dimerisation].
TAPE ENDS
- A296 -
APPENDIX B
TASK FORMDIATION STUDY
Contents
Page
Table Bl: Task formulations of each item appearing in each B1version of the PS test
Table B2: Item statistics on pre-test and final test B2
Table B3: Distribution of students with respect to test B3version, school, class and gender
Procedure for administration of the PS test B4
Summary key for self-reporting form b7
Comments on cases of difficulty in marking items B8
Marking scheme B9
Table B4: Three-way analysis of variance of VARTOT by test Bllversion, school and gender with covariable MARKRTOT
Tables B5 (1 to 25): Analyses of variance of item scores by B12test version with covariable MARKRTOT
Tables B6 (1 to 23): Two-way analyses of variance of item B37scores by test version and performance fertile with covariable MARKRTOT
Addendum
Problem-solving in O-level chemistry: version A (blue)
Problem-solving in O-level chemistry: version B (green)
Problem-solving in O-level chemistry: version C (yellow)
Problem-solving in O-level chemistry: version D (pink)
Table B1 . Task formulations of each Item appearing In each version of the PS test
Item no Test version - text code (computer code)
test computercode
A(1 ) B(2 ) C(3 ) D(4)
lai 101 S S R A(R)laii 102 S S R A(R )lb 103 S S R A(R )1 c 104 S S R A(R)Id 10 5 M M M M
1 2a 201 A(I ) R A(R ) S! 2b 202 S R A(I ) R
2c_____203 A(I ) S A(R ) S
2d 204 A(I ) S A(R ) S2e 205 A(I ) S A(R) S3a 301 M M M M3b i 302 A(R ) A(I ) S S3bii 303 A(R) A(I ) S S3ci 304 A(R ) A(I ) s R3cii 305 A(R) A(I ) s R4al 401 M M M M4aii 402 M M M M4 b 403 M M M M4c i 404 S A(R) A(I ) S4cii 405 S A(R ) A(I ) S4ciii 40 6 R A(R ) S R5a 501 M M M M5b 502 S S A(R ) A(I)5c 503 S R A(R ) A(I )6 a 601 R A(R) S S6 b 602 M M M M6 c 603 R A(R ) S S7a 701 A(R) S S A(I )7b 702 A(R ) S S A(I )7c 703 A(R ) A(R ) S S
Key: S standard Item A(R) augmented (relevant) itemR reduced Item A(I) augmented (Irrelevant) Item
- B 1
Table B2 Item statistics on pre-test and final test
Item statisticsp = facility d = discrimination
Item numberProtocol analysis (N = 20)
Pilot test (N = 30)
PS test-/
test computer P d P d P dla(l ) 101 .85 .50 - - .60 .40la(il) 102 .85 .50 - - .78 .39lb 103 .45 .33 - - .25 .231 c 104 .10 .33 - - .16 .28
105 .75 .67 - - .37 .562a 201 .65 .67 .47 .60 .72 .402b 202 .80 .17 .66 .60 .83 .322c( 11) 2 03 - - .44 .50 .31 .342d 204 .65 .33 .58 .70 .66 .482e+ 205 .60 .70 .63 .17 .53 .793a 301 .70 .50 .93 .10 .59 .363b( 1) ) 302 .65 .67 .68 .60 .60 .313b(ii) 303 .65 .83 .74 .40 .79 .253c(l)) 304 .40 .67 .37 .80 .60 .323c( 11) 305 . 60 .67 .53 .40 .65 .434a(i) + 401 - -
.23 -.10*.12 .33
4a(ii)+ 402 - - .10 .274b+ 403 - - .81 .20* .49 .304c( 1) 404 - - .56 .00* .52 .024c( 11) 405 - - - -** .11 .104c(111) 406 - - - -** .00 .005a+ 501 .78 .58 - - .27 .565b 502 .50 .33 - - .58 .155c 503 .35 .83 - - .04 .106a 601 .60 .67 - - .34 .44
~ 6 b r ~ 602 .85 .33 - - .46 .526c 603 - - - - . 22 .367a 701 .71 .58 - - .41 .367b
^_________ 702 . 50 .67 - - .24 .257c j 703 .38 .25 - - .08 .15
Key: / standard version of Item (N variable)+ marker Item* Item modified after pre-test** Item replaced after pre-test
Table B3 Distribution of students with respect to test version, school class and gender (tests were distributed at random within each school, or group of schools, le C, E, K and X).
School Class
Version A Version B Version C Version D Overall
F M Total F M Total F M Total F M Total F M Total
C
01 1 3 4 1 4 5 0 3 3 2 2 4 4 12 16
02 5 2 7 3 3 6 0 3 3 0 3 3 8 11 1903 2 0 2 1 3 4 5 1 6 1 4 5 9 8 17
04 5 1 6 3 3 6 2 4 6 2 4 6 12 12 24
Total 13 6 19 8 13 21 7 11 18 5 13 18 33 43 76
E
06 3 3 6 3 2 5 2 2 4 3 2 5 11 9 20
07 1 1 2 3 1 4 3 2 5 0 4 4 7 8 15
Total 4 4 8 6 3 9 5 4 9 3 6 9 18 17 35
K
08 5 0 5 8 0 8 6 0 6 3 0 3 22 0 22
09 5 0 5 2 0 2 4 0 4 6 0 6 17 0 17
Total 10 0 10 10 0 10 10 0 10 9 0 9 39 0 39
X
H 05 1 2 3 2 1 3 1 4 5 0 2 2 4 9 13
L 10 6 0 6 6 0 6 6 0 6 7 0 7 25 0 25
G 11 1 2 3 0 5 5 2 3 5 3 2 5 6 12 18
J 12 3 2 5 0 1 1 1 3 4 1 2 3 5 8 13
13 1 1 2 1 2 3 0 3 3 1 1 2 3 7 10
Total 12 7 19 9 9 18 10 13 23 12 7 19 43 36 79
GRAND TOTAL 39 17 56 33 25 58 32 28 60 29 26 55 133 96 229
Key: F = female M = male
- B3 -
PROCEDURE FOR ADMINISTRATION OF THE PS TEST
1. Distribute the test to all students, instructing them to read and complete the front cover, but not to open it until told to do so. While they are doing this reassure students concerning their anonymity as far as research reporting is concerned but point out that the test will be marked and should be treated seriously as an opportunity for examination prac tice.
2. When all are ready instruct them thus:
Now turn to page 1 where you will find some special instructions. They may look a little complicated at first, but don't worry about that - they are really quite easy to follow and when everyone has read them, I will discuss them with you and answer any questions. For the time being please ignore the loose sheet you will find inside the cover.” (Show them one.)
3. When students are ready (allow about 90-100 seconds) run through the instructions as follows:
3.1 "Now I am going to go over the instructions to make sure everything is understood. The first thing I want you to be clear about is the difference between answers that you remember, that is number (i) at the top of your instructions (show them), and answers that you work out, that's number (ii). Of course you use your memory in answering all questions. The distinction we wantto make is between cases where you remember the answer itself, and those in which you work out the answer from things you remember. If it is the answer itself which you remember then we are talking about the first section in your instructions which consists of simple memory and complex memory."
3.2 "Simple memory hardly needs to be discussed. If, for example, you remember the proportion of oxygen in the air, or the definition of a catalyst, that is likely to be simple memory. If, on the other hand, you are asked how to distinguish between say copper(II) sulphate and iron(II) sulphate, and if both these substances were familiar to you although you had not considered this particular question before, you might be able to answer it simply by remembering certain things about each substance and putting these together to get your answer. This is what we would call complex memory; when separate memories are simply put together withoutany working-out. Another sort of complex memory occurs when the thing we are trying to remember is a bit complicated, or perhaps we don't know it very well and the answer is dragged out of our memory bit-by-bit; you may be able to remember something about the answer, then that leads on to the next part and so on. It may be a bit like finding your way back to a place you've visited only once before, rather a long time ago. You know which direction to set off in and that you have to turn left somewhere but you can't remember where exactly; however you often find that you recognise the correct turning when you get there; the right memory eventually pops up from wherever it was buried. So, the answer remembered in part, or built up step-by-step, is what we are calling complex memory. Now, before we run quickly through the rest are there any questions about simple and complex memory." (Deal quickly with any queries.)
- BA -
3.3 "Now for the answers which have to be worked out; that's the second section in your instructions. First comes the case we call simple rule. This is almost like remembering the answer but not quite! If I asked you what gas is given off when magnesium reacts with citric acid most of you would correctly say hydrogen. Now unless you have seen or read about this particular reaction, which is not very likely, you can't simply be remembering it. What you probably remembered is a simple rule which fits the question, that is acid plus metal makes hydrogen, and this leads straight to the answer. To be called a simple rule it must fit the question and lead straight to the answer. I hope that one is clear. Application and comparison are next on the list and I don't think I will need to say very much about these. Application is when an answer is worked out by applying certain chemical principles or knowledge to the problem. Of course you will be using your memory too but the important thing, as far as we are concerned, is that the answer itself is not remembered, only some of the things neededto work it out. The working-out bit is what we are after and we are referring to something less direct than a simple rule. For example, and I'm using the example from your instructions here (indicate the place) if you are asked how the yield of a particular reaction is affected by an increase of pressure, you have to remember and apply le Chatelier's principle (or whatever rule you use) and then work out the equation and count up the molecules of gas on each side and so on and so on. So that's application. Comparison is when you work from a particular example rather than from general principles. I might, for instance, ask you what happens when sulphur dioxide is bubbled into lime water. Of course you might be able to answer this in many ways. You might have done this reaction and simply remember it, or you may be able to apply the proper chemical principles and knowledge and work it out that way. However some pupils might try to get at the answer by comparison with the more familiar examine of carbon dioxide and lime water. So to summarise, the answer may be worked out in three ways: by a simple rule which leads straight to the answer by applying chemical principles or knowledge, or through comparison with some other, better known, example. Are there any questions about these three strategies?" (Deal quickly with any queries.)
3.4 "Finally section three on your instructions: guessing. We can deal with this very quickly. Blind guessing is a complete shot in the dark, while what we are calling calculated guessing meansthat you have been able to eliminate some possibilities, or have got some of the way to the answer, before having to guess. If you look at the example given in the table in the middle of your instructions (point it out) you will see that a pupil seems to have tried to answer a question by application at first, but then had to make a calculated guess when he got stuck. Incidentally notice that if you try more than one different strategy on a question you should mark more than one of the little boxes and explain what you did in the notes that you add. Returning to guessing; it occasionally happens that someone feels pretty sure they know an answer without having any idea at all how they got it. If that happens the best bet is probably to record it as a blind or a calculated guess, show that you are confident about it by writing a 3 or a 4 in the little box at the end (point it out) and explain in the notes that it was a sort of intuition, or however you like to describe it.
- B5 -
f
y
4. "Now before you actually start the test let me make sure everyone understands about filling In the form which appears opposite every question. (Open a typical page to show them.) There is an example of a completed one in the middle of your instruction sheet. The questions are all in short parts and when you reach each part the first thing to do is to answer it of course. Just write in your answer in the usual way. Then before going on to the next part quickly complete the report form on the opposite page. You have a summary key on a separate sheet of paper (hold one up) so that you do not have to remember all the different strategies. First you write the question number - look at the example (point it out) - then tick the box corresponding to the strategy you used in attempting the question, and fill in a 1, 2, 3 or 4 to show how certain you are that your answer is correct. Finally add a very brief note to explain a bit more about how you arrived at your answer. Although these notes should be brief and have not been mentioned until last they are probably the most important part of all, and we have indicated, on the key here, the sort of notes we want." (Now simply read through these notes on notes from the key - concluding ...)"... Finally if you go back to any question, either because you missed it out first time or because you want another look at it, just add a new tick for the new strategy, if you use a new one, and add some more notes to explain what you have done. Now are there any questions before you start?" (Deal with any quickly.)
5. "Please try to work as quickly as possible. Most of you should have time to attempt all the questions in the one hour allowed. However don't get too bogged down on any one question - if you're stuck, after a few minutes leave it, complete the report form and explain how you got stuck, and hurry on to the next question - you may find time to return to it later. I will give you a time check every 15 minutes. Now turn over the page and good luck."
- B6 -
SUMMARY KEY FOR SELF-REPORTING FORM
Strategy used
Answer remembered:
34 = SIMPLE MEMORY
CM = COMPLEX MEMORY - simple memories combined or step-by-step memory
Answer worked out:
SR = SIMILE RULE - simple rule which leads directly to answer
Ap = APPLICATION - application ofchemical principles or knowledge
Cp = COMPARISON - comparison oranalogy with a similar example
Answer guessed or omitted:
BG = BLIND GUESS - no chemical ideas involved
CG = CALCULATED GUESS - based on partial chan leal knowledge
0 = OMTT - no answer given
Type of notes suggested
No notes necessary
If step-by-step briefly note steps and difficulties (if any)
Briefly indicate the rule used
Show all workings in brief note form
Explain the example used
Explain vrtiy you had to guess under "any difficulties"
Explain v*iat knowledge was used and what the difficulty was
Explain the difficulty
Your confidence in your answer
4 = sure it's OK
3 = probably OK
2 = 50/50
1 = probably wrong
- B7 -
COMMENTS ON CASES OF DIFFICULTY IN MARKING ITEMS
1(c) Students often omitted this item and the answers of those who attempted it suggested that it was unsatisfactory, being both too difficult and too vague. A number of answers related solely to the question of whether more or less product would ultimately be obtained, apparently ignoring the rate of evolution of oxygen and hydrogen which was the intended point of the item. It was impossible to determine whether such students simply did not consider rate or rejected any effect on rates either intuitively or in a reasoned way. Nor is there any simple, satisfactory, answer to the question as interpreted by these students, and the item must be regarded as unsatisfactory.
3(a) The answer expected to this marker item had been some reference to loss of electrons from an atom. However, a number of students, particularly from one class in school E, referred to changes in the oxidation state or valency of an atom, and correct answers of this nature were allowed. When marked in this way the item was of moderate difficulty and discriminated very well.
4(a) This marker item proved unexpectedly difficult and discussions with teachers suggested that, while students were familiar with appropriate reactions and reagents, they would not have encountered tests for reducing agents as such. Many students refused to speculate and omitted the item but a number made fair attempts and, with partial credit not appropriate in the context of the investigation, a generous marking procedure (as described) was adopted. Although the item still proved difficult, it discriminated well.
4(c) Although the topic of the simple cell is specifically mentioned in the syllabus as an example of a redox system, several teachers stated that the cell was studied in physics rather than in chemistry. Answers showed much confusion with electrolysis and even part (i), which was answered fairly satisfactorily, was quite often altered when part (iii) was considered. Indeed part (iii) must be considered an unsatisfactory item on the grounds that (a) only two answers out of 229 matched that intended by the marking scheme, (b) no acceptable, but more generous, marking scheme could be devised, and (c) the answer depended too closely on those given to the two previous items. There was evidence of some "juggling", by an appreciable number of students, to render answers to parts (i), (ii) and (iii) compatible in their own minds and this must cast some doubt on the value of these items.
5(b) Students obviously found it difficult, in the context of this item at least, to discriminate between testing for the presence of water and determining if a liquid is water. The latter is not necessarily a simple matter, as a few excellent answers indicated, but to obtain a reasonable facility level a generous marking scheme was adopted.
7(c) Again a generous marking scheme was employed to try to raise the facility level of this item, but it was regarded as essential to retain reference to both a suitable operational procedure and an observable difference in outcome. Even this minlmun stipulation (with generous disregard to detail providing nothing was stated which positively excluded a successful outcome) eliminated answers from many students who appeared to have the appropriate knowledge but failed to evaluate the minimum demands of this type of item.
- B8
PROBLEM-SOLVING IN O-LEVEL CHEMISTRY
Marking scheme
1 mark awarded for each correct/acceptable answer; no fractional marks
1(a)(1) oxygen; 0^ acceptable (ii) hydrogen; acceptable
(b) any reference to the solubility of the anode product acceptable
(c) no effect; any answer clearly indicating that the rate of evolution of products would be unaffected (ignoring any predictions regarding the amount of products evolved) acceptable
(d) any answer contrasting the carrying of current/charge by ions in the first case and by electrons in the second; answers stressing the exchange of electrons between electrode and ion in the first case acceptable if it is also made clear that ions move to the electrodes
2(a) E and J (b) L and M
(c) X (d) G
(e) X^M; MX^ acceptable; charges of correct sign (X +ve, M -ve) do not invalidate answer even if incorrect in number providing formula is correct
3(a) any reference to loss of electrons; references to an increase in the oxidation state/number of an atom or to an (algebraic) increase in valency acceptable
(b) (i) H (ii) Cu
(c) (i) contact process (ii) Haber (Haber-Bosch) process
4(a)(i) any reasonable statement employing KMnO^ or K^Cr 0 (ie any any statement which does not include conditions which positively exclude a successful test); use of Fehiing's/Benedict's reagents acceptable; use of iron(III) chloride Associated with colour change or subsequent acceptable test for Fe (aq)) also acceptable (question clearly unfamiliar to pupils; those describing test with chances of success, given conditions not positively excluding this, to be given benefit of doubt)
(ii) as appropriate to previous part
4(b) cathode or negative electrode
(c)(i) copper
(ii) zinc electrode dissolves forming zinc ions; appropriate equations or symbols acceptable; simple reference to metal dissolving/corroding etc, without reference to a product, unacceptable
(iii) electrons released at the zinc electrode, resulting i^ flow of electrons through external circuit to copper electrode, where H ions are discharged forming hydrogen gas; simple references to the evolution of hydrogen or to polarisation, without further explanation, unacceptable
- B9 -
5(a) (NH4)2C03; any ionic charges shown to be ignored
(b) generous marking necessary; any reference to a suitable physical measurement quoting the appropriate value (with or without conditions) acceptable; tests indicating the presence only of water fee with CnSO. or CoCl2 ) NOT acceptable -------- 4
6(a) chlorine; Cl and Cl2 acceptable
(b) ammonia; NH^ acceptable; ammonium, ammonium hydroxide unaceptable
(c) sulphur dioxide; S02 acceptable
7(a) sodium stearate or recognisable sodium (or potassium) salt of appropriate fatty acid
(b) acceptable answer must refer to both (i) the presence in hard water of calcium or magnesium salts or ions and (ii) the reaction of these with soap (chemical name not essential) forming a scum or an insoluble compound etc; reference to impossible salts under (i) above - generally to CaCO^ — invalidate the answer
(c) acceptable answer must refer (i) to appropriate procedureand (ii) to a correct and observable difference in outcome, properly attributed to appropriate compounds; providing conditions (i) and (ii) are met test acceptable, even if deficient in detail, providing no stated conditions etc positively exclude successful outcome; three potentially acceptable tests were encountered thus:
- heat each and test any gas evolved with lime water; only NaHCO,yields CO2 which turns lime water milky ^
- add each to sample of hard water and shake with soap; Na„CO_ only will soften water giving better lather (although attention to detail is necessary to make this a good test, no half marks available and simple answer as given acceptable)
- dissolve each in water and test with pH paper; Na2CO- will show thehigher pH (further towards the blue end of the spectrum); test with litmus unacceptable as is statement that only Na CO will give an alkaline reaction ^
- BIO -
v /*■ f< t 1
1 r
Table B4: Three-vay analysis of variance of VARTOT by test version,school and gender with covariable MARKRTOT (for mixed schools only
sc n c\> '"C ir sz
^ ? n n s*X »s ^
■C sC n . rv
X . X o c y «—» N —• X S 'TT ■»" X V x X c\ S ' V-«
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- X c\ .*\l r rrs . »V
£ X X ! - X « r X X r\ ~s •7 rC LX O' O' r*- Lf; X c\ X *c •—o o - O ' ry — O 'a . <T —H «-« *r> x - X X r>v r* V N ■wy
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B 11
ITEM
ioj
BY VE
SSIO
N with maskrtut
Table B5(l) Analysis of variance of scores on item 101 by test version with covariable MARKRTOT
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Table B5 (2 ): Analysis of variance of scores on item 102 by test versionwith covariable MARKRTOT
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- B13 -
Table B5(3): Analysis of variance of scores on item 103 by test versionwith covariable MARKRTOT "
u. u s s CMM s <s X OO csz u s es CM CM sCD O • • • • •MCO
X X »n xi •aX X X X Xb. CM CM CM• • • • •ro *o
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U . X O» O» S X Os3 U i O o í n io CM
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t r « y j < POO ►— U l P— V*U . Z #- U i
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Ui Xo oUi Z • - U i « o Q . ZD a i n o3 Z U i < H c
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- j s C P— * CC—• M Z CM
z X X i£ « • >-a i X QC Z*— a J <x « ca# > SJ 3
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_ i *— * < 4 I U C> M II OX * «
Z +■Z Z Z Z X X X X
X « •** OC CL CL JLU i UI a i U i Ui LU
« X 1 Z > > > >wC
« « o •< ►a CM X ^T» M X
** •Il Z ZZ < UI
« « CD > >
- B14 -
SUM
OF
MEAN
SIGNIF
SOURCE OF VARIATION
SQUARES
OF
SQUARE
F OF F
Table B5(4); Analysis of variance of scores on item 104 by test version with covariable MÄRKRT0T
c v O í 9 « ' « a : t o t o < CMs s C to 3 O K U I Ks s ro m 3 « « u . z r - l a •
• • • • • U» < ŒJ* « o o •-»
u i z a« » - tU -ft
CMOS! i n in CM W Q. > 2 in CM CM«O AC 9 9 AO (O * D U O * 3 3 3 3in i n 5 s x r o u > • • • •
• • • • • M « a 2 u j 93 3 r o -ft *-• f t o
<n «
>» «K K «o AO <S m a co <m m r s r s r s I s _ j « C K KI S IS 3 3 CM 3 3 lL 2 l i i
• • • . • • • • •ft * UJ CEÛ O
2 « U i 2 r - U i
•< « CO CL 2 D u i ft n oo z u
2 ft c :
O «in tn M- GO
CM CM M ft O -ftCM CM U i »— V«
r - * » - UJCO
•
* 3“ 5 3 — cm ro
r s ^ ov o» AO S in u ft O - S S 3 3ro r ) CM CM o CM GO <£ > • • • •r s r s CM CM 9 vO *-♦ « 2 UJ V •
• • • • • • • ZD 3in o U . *»" 4
*
CO «
CO « 3 vc go 3 in *n «n •o in
•< ft—J «
«
*
UJ 1 - «*3- 3 -J ® O ' ^ »—• cl x <o uj cr#—» ►— Lu
it ft •ft « c<-3
ft- « U i3
- i ft- * •ft •ft cc u cCO >- M II o
►— ►— 2 2D S « 2 Z 2 ZCO 3 O 2 -9 ft to CO CO COu i f t u i O C . X * "ft c r cl a : anft- a : U . u i u i U i u i u i u i UJ< i t U . CO 2 < •ft X - J Z > > > >•-* c r u i a : M 3 cc cÛC ** U i •ft 3 - i •• ft O •ft •h ^ w r ^< 2 2 > —J »—• < 2 ►ft CO> ft* CL CO r - * ft •ft a: a :O -ft X UJ c a •ft UJu T U i or »— ft ft C3 > >
B15
SUN
(JF
Mt’4
N SI
GNIO
SüHM
rt O
P VA
PIAT
TîjN
SUUA
HfcS
OF
SQ
UARE
F
OF F
Table B5(5) Analysis of variance of scores on item 201 by test version with covarlable MARKRTOT
c s. »r TT * « crten m ^ w G G r-G G ® G G * « U. z• • • • • Ui« « g ciLz« fr— UiO O' cm cm vO enGiß ir <c <c ET ce « 3 «4JN rs sC vC O "3Q• • • • • ■I* C ZTI TJ *■> m m <r*—«te *>- ■dO O TJ rs. G CM crO OS TT T7 TJ -J « 3CS G cc « Os CM CM U.• • • • • • • << •d—• —* Gz « U*frc ■* ieG«d •-5G•d <O •«•*5 T? TJ •J X<\ CM ►— «CM CM »- •d<i «d
vC vC rs TT G «O* O» -n fo CM 3 "O*Z G *r> *n •û sC CM t-t •d• • • • • • •CM CM ir U. •dr G) *“ ■d
te *te •d< «—i *G «
«U. •d—* G'T.C F— ■d eCi*—* ßa. r te « •ai“C .'C►-U. *3r- «
■d5 >-►a ilF— • *vO G O — 3ui ►— tèj G G « •c*— or U. r-fr ai -j -i< JL o> CO Z <3 ■* z•-» G Ui ÍT 3OC <j (kl < G _i « •d G
T. G > -1 •-* < 3> a cr ■d «d cO <ï X ai o crO X U. O' •— * -d G
B16
iJNAOJllfiTfcn
IMUEPENOENTS
♦ COVA
RIAT
FS
vari
amil
♦
catf
uhuy
n
devo
fta
oevn
reta
dfvn
reta
nv V
f.r'Si
ri.i
WITH ; IA i< K !< T II T
Table B5(6): Analysis of variance of scores on Item 202 by test versionwith covariable MARKRTOT
41 « U Ik . i T . iC i n 4* C t t / i»— » G © CM CM c a O
41 « 2 L k G ; G C L a . 4 l 4t U . 2o c • • • • • U t
41 « fr 41 41 C Ce o U J 2
41 « 4T *— U JC M CM i T S i ¡ n c o c l
* « « C i « c c e < r G - V i 4* 2 L Ju . o c c o « - « "“3 3
41 41 • • • • 9 >— • 41 C Z■ s : s r o i n < 1 * -*
41 4» — — . CO 4 l
i t 4 » > » 412 u i v O S i s S «C e t
i t 4» *«* o r C O S C K N r v » 4 CM . 41 cM U < J o c r u v C X > CM CM La.
i t 4 i X ~ • • • • • • • < 4 ic ? r u c m O
J J 4* CO 2 41 L UE—
U 4 i *<* 41 < o
2 « 41
< 41 2 41 < x
4r Hu . P T -O - t "C
û : 4r C , CM CM i— i 41CM CM
4* • - 41
> 4 t « s 4 i
4s Lk. C O S V « « -« r s vC CM O 413 mJ C O CC •—4 c . rO - ï
u . 41 a : C M ( \ G 3 c v »— » 41r < j • • • • • • •
c : 41 2 3 C M C\ CM CM _ . t 41O 3 T S i
H CO •— 41
V i i t X 41
- n JO 41
c o M c 4t
>■ H : 4i
B17
UMAO
JUST
EH
iHnEPENUFNTS
t CD
VARI
ATES
A R1A h l, L ♦ CATFoOtV
M [)E V ' N
ETA
DE V ' N
RETA
OEV'M
BETA
Table B5(7): Analysis of variance of scores on item 203 by test versionwith covariable MARKRTOT
« * U_ u . o Z a ♦ « C L X X <J Ps*—• CM CM «a c »— u i »—¥ « 2 U . S C s . z S *#1 « kL- z »“ lL- •19 C • • • • • U j <r co¥ * M « ■R r~. c: H»X LkJ ir
4* * * ¥— Ui <CM CM TJ ic X a > z vo m a -o¥ * *C vC O“ O ' X X * ÜJ c • E S 5. -u . CM CM tr- o o -> • • • •■* HR • • • • • •—* ¥ e z Ui • i •S i Si CM CM rO < ►4+ ZHR * X ¥
¥ >“ ¥Z u i in Si m m *C pn 4^ Ct X 44¥ * < a : in sì o o s _ i ¥ o H ►—u j < . z s ì in CM u . Z U i♦ « X z • • • • • • • ¥ u - X
<2 c c .U i * X z ¥ O-k— u iL ¥ •c. ¥ X a z
: ; —*- ¥ ¥ £L >
■t*. «T o J< ¥ ¥ *— c
¥ c ¥u_ —• ««i m ~ i T cccr ¥ c . CM cv ►—1 ¥ z < O'
CM CM u i ^■< ¥ 1— ¥ 1— u. •X> ¥ <r ¥- ? X X ." î X
¥ ÜL X m s 'S Z' IT X c_> ¥ c - Z . T 4-Z u i Si Si ,"*i r*- X X Q < > • • • •Ifc- ¥ a. IT“ T- «■r; •r c\ >c ■■u ¥ Z u. 1 1 •
• • • • • • • z zCZ ¥ _. __ T-* *4 c\ »T s. lx. ¥X ^
¥ X •— ¥
cr ¥ S i ¥
— ¥ X ¥ -C CC T SiS Si c s.X ¥ <r ¥
V ¥ — ¥
- ¥ c_ ¥
¥ ¥
- H ¥ u. ►- ¥s — ~
<1 c ¥ __ -£ /£ ►— ¥ lCex •—« •X ru V—I CM* 2 >L ¥ X C . X X JC ¥ • >-
•Z t X¥ ►— — < i * ►— • t— CM < ¥ “*— *-4 > 7*
¥ <r »— ¥ u .V Z —t V—« X >— « Q: ¥ <1 <* Z o z
—* <T Si •>- • -4 II4* i . ¥ > >— k— X TP ¥ 2 Ü Z 2Si c - o ; 1 /T ♦ O O X X¥ ¥ Uk. U- ►“ u C o . a; ¥ 44 ¡L 1 i '1
w * - X a_ — . . lU u i -kJ u i u ^u♦ ¥ «1 X u . X Z < ¥ s > > > >UJ ►-» 2 : u_ zs. »-4 ~* X z4* ¥ l_ ' a -a u* -c C i 1 ■« « ¿2. <x T-. CM m ryX < z z >■ - i M M X♦ ¥ z > a . X b— 4t ¥ < a az z ■«f X U i o ¡V ■< u J¥ ¥ X l_> TZ lx* a *— ■R ¥ > >
B 18 -
1 TH
iIAk
KKTO
T
Table B5(8) Analysis of variance of scores on item 204 by test version with covariable MARKRTOT
***«•*
«****
*
**•w*•*«
•ft•ft•ft•ft
*ft«•««ft
LU. — —21 U_CD C
ft Q:u; <X 3
3 <o
crX <
ft* • — CM (M ft ft a «/ î i/ : <c s s . vC \ c S i O > - a i fr—s s ft" ft* C£ « ft k l. Z # - U¿
• • • • • a J < Cft ft C C lu z a
ft ►- U J •«*c o •C <c CM W Û . > 7cc c c CM CM a co « 3 ü » C •
rs . ^ X T C Ü >• • • • • *—• ft C Z u .m *o ft* tv f t ►-* u - gCM (V <o ft
> ftc c .n in fN f t - cl <n <i«*> K3 r s rv Tf « — V -1 ft O k— »—
s m pò n CM CM Il Z L J• • • • • • • <3 ft U . CC
.n m —* O 3z ft lu i Zt - u Jft ft CO G . Z2 U -ft c > C Z d jz ft ft ►- c,
c ftpr **> ■c *
CM CM ft w ftCM CM
I- ft Lk- ►- •- ü_<n
ft ft3» zcra m in V T* X u ft c. -
CM CM n Fv O <t :>ÎTS *—• -- *— ■c CO *—* ft X LU•• • • • • m 3 343 — ft- >c X •r u. ft
cocn
cm .n is rv5 2, g
C .3 CiZm T*• • • • I I
o r x it.otf’ o *r
CM —* jL a X \ r * ft *j r*— •— U. «4 «—♦ > T
©co
«J >- * ■ftX L cCO II o*— ►— 3 Ci.' ~ï ft X 7 2 XlO vJ Z “3 ft n «.O</>.oé4-►— ft- L-> ■ > 2. ft ft -T ft a»— cr U. »-* mJ -J UJuitUaJft ft U. tO X ft ft X z ;> ->> >12. uu c: •—* z 3et ft UJ ft Cl « ft c- ft ►— CMK* T3ft X Z > -J é—« ft 3 0)> a «O K- ♦ ft ft a: a3 ft X UJ o ft ft UJLJ X UJ 2C ►— ■* ft C > >
B 19
•** 1 T
f i • i A h* K M T u T
Table B5(9) Analysis of variance of scores on item 205 by test version with covariable MARKRTOT
<* a . u . —* ~ Cm CV. ~4 * * ac co (A < TO<s o CD CO *2 O H U J K* * 2 u . c CM CM ♦ * U> Z: H* tu •
o o • • • • • u j < ; r■* * M * * c c •-in L*j 3 n :<* * ►— Uu <1N N O ' O ' «C « g. > z cn x -* in* * XI XT rv rv o CO ■* Z3 U- C — —= G x z.u. tn in CM CM ¡s •o c. sj > • • • •♦ •* • • • • • •-X * ¿3 3 Ju • •-o x in < •-* + C.■* •* *
* ♦ > *2 vu XI XT O O i *3 5. II CC5 <■It * < a x s> o o O m S'. <* GLia <* X X CM CM • CM CM a . 2 u i♦ * r ~ • • • • • • • •a ■It L_ Xc? "> rO
u i ■* x 2 « X z*— UJ
o « ■< •m X X 3~ li •¿1 •# ■* "3 C >3 Z ui41 * < *- C
•-* •* C <*u. »** m XI XT X0: •* c. CM CM _ * a <« NCM CM U i 1—<* •* H- + »- Uj •
CO> ■* < ■ftLu C/3 XT TJO u J C□: X XH <5 • •~ ~ ro rr00 3
¡r
x xo c* x cc Ps
XT
XfOcmS i
fs a .in
c • ^ X w p. •“ Cv• • • • I »
X%r. vC X r_ cr. iD «r x m
B20
version
Table B5(11).___ Analysis of variance of scores on Item 303 by test versionwith covariable MARKRTOT ~ —
* * a. u cc cc•—* *0 *o •s. s
« + Z U. s s. <s s &o 3 • • • • •
« « *—«to
4tcc cc
* « in i t cv cm XLi. "O f*0 rv CC
* * • • • • ■^ xr N N «O
« «
* «Z u l oc co CC CO O CM
•* * "C ft <c <c ^ •- CMLki «X o» <7» K K «r> CM
* ♦ T 3 • • • • • •Ç9
Uj «•r CO
CJ •m
- *
•< 4C
a—1 *u. f t *—> *r rj
ct « c cvCM
•*
> «
« Li. CO cc cc r .3 UJ 3 3 •Tj «T3 Tw ftU» * 2: ft ft w «•* rvX <t • • • • • •c 4» 3 3 ir ir O ftiO 3 *7
M CO
CO *
- 4*
C/T 4»
>- +
— -at
*
r »— 4*—
<1 ~ ~ ►— «
♦ £ JO X 4r —;c V
4« « - a.1■< -* •—r—♦ T» T! t—
« 4r <.>- t—,
4C X *- « aM < to« r « » ►— fr
i/2 3 u ì Z* 4« u. IMJ +~ Caí C 3
o ►— a: .. ►-* OJ -J« ■* •a jt U. tO Zui — • a u i a a—t 3*
« * CJ a <t a. <* rcc < r rr > -1 <H
•H « 3 > 3, tTo o >< X aJ* 4» to u r UJ 0:
- B22
« * ÛC to to <Jo H Ui H m■n « La.Z h Ui •U. < 3« « C c-J z a« *-LU <2toa > 3(O « 3 UiC - a s t Û u > i l a «* C z uj »M ♦ Cto «>- «Lf3 3r t/3 <”7 -/ * C *- 1-CM Là. Z ui• ■<* * u. CCC- 3z « Uj Z*- UJ<i •* <o a zD U --* •■o c >3 Z LU•* <* •- Cc «XCV ►—1 + C <r CMCM UJ»- * K u •to< ■¥ ^ 3 7 v>fO CJ « 3 • CM t T- —< > • • • •ft H* « Z Uj •• z oIT La. «X. *CO «cc « r r X t ipiT *Tj O JO*— «CJ «
■**~3 *
—( c. cf ►— « or“O «—«■Va : to X 41 • >-UJ X t wC^ * c—* > 3 3*— <* La3 ►—«i ♦— « c <1 X 3 3>- —« «i u>3 3 41 z z z z— u ^ .0 .0 oZ 41 ft ex a auú oJ uJ oJ «Ai oJ4C 2.' —■ 3 > > > >CM 4i 3 <r •— - a T»< 3 M JOi- « * <r a ao QC <T UJf— •« 41 cr > >■
I Tt-’J-M
Table B5(12) Analysis of variance of scores on Item 304 with covariable MARKRTOT
by test version
ft « a . u . r * c cs ft ft—* «-* TT TT CM
ft ♦ 2 Ll. <£ s . X X ft ftO O • • • • •ft « *-* ft ftCO
ft « ftrs. n * c r <yft ♦ K" r e rv rv ■»3 tr. ft
u . in in CM CM CDft ft • • • • m •—• ft«o *c « i•ft * CO ft
ft •ft >- ft2T u j in m «-4 — CM X
ft ft •ft a : CM CM <C VC •s CM ftb J < TT XJ iS v i CM Cm
ft ft X 3 • • • • • ■ • •ft ftC3 «»-* *—•
i l i ft «n 2 f t
U ft •ft ft
2 ft ft
< ft 2 ft
f t 2 ft»■* •*} fT» •<? ■7 X
a ft 3 CM CM *-* ftCM CM
< ft ft
> ft f t ft
ft i i - CO *r. in rr -n X O fM ftC? CM rs* x oc CM ro
u . f t <%» •C t j C X •3 ►— ft2 < • • • • • • •
3 ft Z» 3 — ^ X U. ftCO 75 MDft CO ft
a en c . >- u . z
il ic c uj Xfc- It*t r a.r u- cC. 2 < *-*
crcL.aIo-Aio3<
B23
UNAD jll$Tfc l'
IlfhhPf N
DFNTS
t cn
vART
ATES
^A^lAiiU ♦
c A T F iif'i' Y
N OFV'N
FTA
DF.V'li
Hf T A
DFV'N
BFT A
10 iV|H V*-' 1*1 td f' 01S V 3A
AH ‘Mfhlll
Table B5(13): Analysis of variance of scores on item 305 by test version with covariable MARKRTOT
ft ft u . u_ ^ • - iC X. O ftM cv cv C Gft ft z u . e ® o a cv ft
o a • • • • •ft ft ftCOft ft
x- IT; JO xXft ft N Ps X X X cr
kk m ■•o •d *4 T!ft ft • • • • • #—»UO xX
ft ft CO
ft «Z UJ >o >o g , rs, TO
>-
ft ft •ft Or ac x V -V CV cv CV « JU* ft xx s s . PO cv cv
* « Z 3 • • • • • • • ft3 xX «-X
ft to Z 1
u ft ft
«
•ft ft z
ft cu. XX XX •n *r TT X
a « c. c\ cv x_.cv cv
* >—
> ft ft
« Ik. CO kC SC k ; f*7 a. a PV CJ3 u i CC *S rj cv ■C rx>
Ll. ft or xx X-* X* XX pn PS Mz ft • • • • • • •
c ft ~ 3- XX z~. ¡Ju-0 3 S
« J?
tr •« CO
ft sr
cr •« ft•>- ft
f t O: i/5 CT <C Mj *-* u. Z U.
u J < £ ft C i CJ *—Ui z a ■* P— LU <*W C L > 7
♦ t Ia j C --7 C i U >
f t C 2 U -•ft •-* ft* Q ft
CV cv cv e c <s ct • • • • i i
*cr co <x
ft c P- p-u_ Z uJ
«o
ui XO
ft aJ z»- UJ
ft CO c. zz uJ -
ft c >r*. 2 LkJ
ft •ft »— c.ftft o •«*
UJ p—ft P- UJ
COft ~*-j z T* f\| xX
ft o - ? o s cr< > • • • •ft z u; » •
ftft*♦•ft
c « z /iT -T v J Z )
■a
ft
ftft
B24
I T T ■ 14 n 4
hv vf-liSiriN
WITH .
IAKKHT
mT
Table B5(14): Analysis of variance of scores on item 404 by test version with covariable MARKRTOT
♦ 41 U. U. ig m tft tO G 4» HR 2 CO </) < aoM m m PO c *— uj ►— s
« * Z u. K IN N N 00 4t 41 k Z •- Ui •G O • • • • • UJ *«f 32
« * 41 41 0 3 * -cn ItJ? 2
HR 41 41 K lL <•*£ vC TT ^ G CO CL > 3 ~ *f> CM
♦ 4t v- ^ IT IX rv W 41 3 U-- C - C f s &ik. r» ^ m T C U > • • • •
* « • • • • ■ •—» 4t 0 3 UJ • •<* »-»-•* G
« 41 to 41* > 4i
2 U4 ai ei TX rO CM O' o: to41 * «* a; cv cm •m* O iT T7 _J 4t O ►“ H-
aJ <1 o ^ —* «-• c CM CM Ll Z Ui* « x g • • • • • • c -<x HR uj tr
Q o aUJ 41 CO 41 UJ 3
*- UJo ♦ < 41 « a 7—’ ~Lt •2 4i o c >
O 3 UJ<i ♦ 2 41 <* — c
4i C 41m m CO
cr •* c CM CM »—♦ 41 C. <1 ccCM CM ULi H-
< 41 *— 41 >- U. •CO
> * •<* 41 3-3 r n ’X cm
« u. w O O rO IT' C V x O u 41 G - CL <T E G3 ^ O J CM ’T T r*v c < t > • • • •
U . 41 o r C- 3 m ro ro vr- N *—1 41 3 U_* • I3 < • • • • • • • 3 a
c 4» 3 3 x X (X. 41X 3 JO JO
41 to »— 41Si 4» X 41
4» <x 41 - x x r* xj4.0 lO C ¿A
CO 4f <a 4i
V 4» — 41
4t L 4»
cc
0: <*< G >
tO*—U 3 «A* Gu. *-*U. to
LL>3 ><rT.
a.XUJ
cMtoUJor
u . ►— 4lT
c * - 41 i TCJ S)
a. r iO ■« • >1 •r zc
* - >— UJ < 4i c*> tr. 13
h- 41 UjT. *— 4l < < 2 U C
>- *—♦ II Oa 41 «L 3
cO lO -0 OIt <i J £r a j
Q:<T>
—« —• fM rr ^-oo:
- B25 -
I TL
M'.'S
by
vM.s
Siru
"I Til flAn'KIUijt
Table B5(15) * Analysis of variance of scores on item 405 by test version with covariable MARKRTOT
ft « U . U- — S 3 E * ft Ct COM s 3 Ps P s ■ ^ 0 ►—ft ft z u . IS 5 r r p r C « ft u . z .LD O • • • • • LjJft 4r M ft •ft 0 c .ft ft
COft
LaJ ZP - UJ
• 0 i*> CO CO 0 .ft •41 r s p s ir i r G < 0 ft ZD u Ju . r r - J c .ft ft • • ■ • • ft c zm <1 1—*ft ft to ft
ft ft >> ftZ u J f s r s 1 0 >n oo *3 QC•41 ft •ft or ^ KP 0 0 s . o* O ft 0UJ O l C? ! m zl PO u>ft ft X z • • • 9 • • • <f ft
3 f-yUJ •ft CO ft «iml
h~O •ft •ft ft CO
3*- ft ft —>
■< ft z ft <•-* ft c ft
u . n 'n COCt ft c CM CM *-* ftCM CM<r ft ►— ft
> ft f t ft
ft u . CO Pv PS vC -c CM CM UT u ft3 wA - r «3- flC IO O CO
•L ft a : O' O CM CM CM CM V *_ ftz <t • • • 9 9 • •c ft u . ft
0 3 CM cmft CO ft
iO ft < 0 ftft to ft
to ft f t ft>- ft — ft
— ft ft
B26
UHAOjHSTfc n
IfintPfMUENTS
+ CflVAWlATES
VAHlAFill
t CATFoC.fY
>1 OF V ’ M
F T A
OtV'N
Rfc T A
DFV'N
BETA
Table B5 (16 ):___Analysis of variance of scores on item 406 by test versionwith covariable MARKRTOT
« « U. U. rr ro cc OC C * ♦ a: co co ■<»—♦ CM CM CM CM c k- UJ *—♦ * z u. s s ■£, * « u_ Z ►- lic? o • • • • • Ui <t er* « <11 C C. »—*CO u* z a:<#r « « ►- Lkj <1Pv K cn iß a > 3 — — — ro« « e cs «• «* PO cr. * 3 u. C — S <S S SIk. CM cm O' o> N "-3 C 4J > • • • •* * • • • • • M * C Z UJ 1 • 1in m «-» —» CM < M +< o« <* to *•* <* >- •*Z Ui V TT »O CO o □C CO <c* « < or •*? TJ «-H CM 3v —» « c »— k—ai 3. «5 •"5 *3 rr ¿Si sS u- Z UJ<* ♦ X 12 • • • • • • • «* « •AJ XC5 O 3Lu « co z <* Uj Zoz
a•a>
<o>-
**■*
♦■*
L i. — « a m m T* XCM CMCM CM
u. C O a a CM PO3 U J * T C i J i CO
0 1 .3 © 3 ! CP O 'Z < • • » • • • •__ 3 —
• o 3
CO
U
«««*♦<*<#«<*
UJw a. rc >2 Z U <t *-* C.
C <5uj >—
rr «■4 «a— PO— S PS .3, c> • • • •Ui 1 • •
¿ X : ir«n >2 <0 »Ci
rr<:>
<1 'X es-c.co vO eOa a. a aj j -i UJ «-J3 >• -> > >
CM fO •*ïlOor■>
B27
lTl«
!iU2
HY
Vf n
siili,
1 Ti)
i! Añ'K K Tt
,T
Table B5(17): Analysis of variance of scores on Item 502 by test versionwith covariable MARKRTOT
« « U . U» X X N t v o .M CS* OJ m in s
« « G U . O ' O s s .G O • • • • •
« « *-*ex
* *O O X X
* « s e . V TJu . t e *n Os
♦ ♦ ■ • • • •CM CM
« «
« *G Lü CM CM CM CM CM TJ
* it < a : CL. <S. vC X CM CM CMU i <1 S ÎS íTS *n CM CM
* « G G • • • • • • •3u- «
KJ *
G *< *•"* ■*
U.a G
< «
> •*
■« U . X G a J
U . •K aG. *4
G ■f« _ ~
* <o
vO «
ro m XCM CMCM r*
C\ CM X X X a~i i X X X CMg r. X X X TT —• • • • 9 •O'T•-O
■<r.
>•
♦
c ♦««
★♦«
* g : co co <iG ►— Ll ’ ►—
* U . 2T ►— UJili «* ££* G G ►-*àia ? ÛC* t— <r WC. > 2ü G U* C —"-a G o >* C G U<C
(fl *> « a: co <r—1 « c ►- »-*U- G LL*< * ¿i* XG GG •* U*TT*— aJ<1 « CT>G G.~***L, •* •"3 ~ >G G liaG •* •— GC *
_ •* G •<aJ *—« ►“ LlX■c « G“> GG * < >*—♦ * G üJw GU. «- ilX «c/> « G-c *—1 *(J «
*K -*T ",-j r 3 ►- ■9 ■CX) *—4rt -#îG 2. to a. « • >*a, .£*— a» < « CT ■3►- * a.Tl *—_ fr- « <>-•— II JG X j. -fl
rz ♦G « <a— 1 jJil il 22.Ü il G •<G
+ ir *< aor <*4C it G >
2J. •-* ifl ^
I •
X
C* —* j"î "Ñ?G G S —
x x r XX Xs X Xi
-a X t_
(O Si toCl oc a. ;Xa i a i *—2 > > > >
M - f v T ^iO ü: a i >
i'UMV.'iVu H|I*
Table B5(18) Analysis of variance of scores on Item 503 by test version with covarlable MARKRTOT
* « ¿L. U. oc oc _ «*-u o CM CM« * Ü u. s rz c *3 o • • • • •« ♦ ►— 41CO4r •«1 a\ o «r N« « oc oc ce OC ir COII. »4 «-• T w CO4r * • • • • •ce ce *H -O >c4c •It —* — to4f 4c z: uj "O CM •o rO >-* •* *«3 a c r T rs- m vO Nu. < CM CM CM CM .3 S* « T“ w • • • • • • •3 w m 4UJ * COo * <- «< « s—» « r
U. k; »o cecr « CM (YCM CM< ♦ f—> « <
« Ll CO w TI 5: -s- a* <C iO oO wJ 3 3 N rou. 4t a <V CM •C X, ce rv un t-4r <f • • • • • • •3 « 3 3» «_ —- r» c u_.0 3 w« CO »-40 « CO— « CTwT ♦ <j
4 i a c o CO •<3 fr l u f r -
4 « U . iz H UiLU < c e
41 C C *—»u . 3 IL
4 r 4— L u <1.CO 0 . >
4c 3 U . C •- J 3 o >
4c C I ? U .< r « •fr 3
4c
4cc r e o « r
4c c H - » -u . 3 U j
4c II . CL3 3
4 ( LkJ 2►- U J
4c CO CL Z ’3 U J —
4C - 1 C >3 3 ü J
4* < M C.
■w •c tv IV S S S B • • • • » I
41 O <Lu ►-
4c fr— Lu<0
4C 3*3 ZL O4f c- - c i s
« t > • •4T 3 UJ • 1
3 O
c X r I siT> *r. -c s*
««*
«
«fr-
~T 3, C 41 ur> X 3 ,
Û. 1 cO X’ 4» • >-«u f r __ 3
•— »— UJ < 4C 37* 3
fr~-
4»i t
« j ►- 4» <x •t .X c_ C>- •-4 II s J
3 4C 3 3 3 33 ♦ 0 0 t r O
X 4C < •X X a .a J UJ u J UJ
41 3 _ J 3 > > > >X 3
41 4r C •«a CM ■O T»3 M co
4t 4« «T a Qcor •< Lu
4r 4C 3 ■> >
B29
nt-vu
nr Vfws
in¡,
f I
T, (
MA
KH
Fî T
i J T
Table B5(19): Analysis of variance of scores on item 601 by test versionwith covariable MARKRTOT
« ♦ O. LL. 4 4-4 S *s 4 *M S Í3 3♦ « z a. s. 3 TJ M C *O O • • • • •* * ►*4 ■*in* « «4 «-* S> iC TJ* * vC «O vC v£ 4 C/3
a. ^ m <7* Ov OC* * m m ■ • • 1-4m♦ * CM CM CO
* « >-Z ai (M CM in in T» so w« « -t a fO fO _ «_* O (M TJ —iLaJ <2 -O X) CM CM CM CM CM« « £ Z • • • • • • •Cï ^ TT -1 iai * in Z
U « <x«
<J « 2•—t -* wU- «■4 —4 rO O -J X<£ * a (M CM ►■4/ CM (M<î * »—> * <t
« u. en CM CM TJ TT K CM er LJz ai »O fO TT TJ N ■O roU. « a iT» 'O C* —. ce > ■—T -t • • • • • • •« 3 3 TJ TJ m O T. U_-O r? T Sì« cr.
1T * 'X- * tet/; « c
>- + —_ M w
****«*<•
O: tn </3 «a
üi< £ û Cl HujZ tr *— Ll- «xin Q. > ZT w U >o z u;
T C O 5 5 . 3 G . CT
• ■ • • • •
*a w <« C K ►-U - Z Lu* u, XO O« ►— Ui* 1/3 a. 23 u j -* -3 C‘ >¡3. Z UJ* < •-* C
* O < CMa i *— 4-4
« f - ÜJ■n
«
■# 3
"3 Z 4-4 O CM♦ O - c ,ç «r •j;
< > • • • •« Z Uj
3 O• 1
*•**
c X •? «nO v/l
< **
«
— «4-4 3 3_ X C ►— « Za *—•31 n
a T! cr X. 4T •-J :j£ JC
►— A— a <J 4« 3, •—#:> i: 3< * UJ
i a « 4t <S X a- a>- >—4 if -J
J»U3 W
►— 3 X JL ■* -, ♦ n •'/3Z Z <n o
vJ — X 4» 4» a a X -r3 *- 31
<x jéa. *“•u» to
ai4» *»»
-AiZ
-Jj>
a*>
ai ai > ->
UJLJ
•-» arÛL -Ö
Ui X ta
»-4T* ¿ a ♦ « C <1 - CM »O TT
çr
Qen
< ZL >OO
Z >*-4*s
__1aXUj
»—»crUJc*
<
OA—
«
*
♦
«
•<
3Q:<>
Q:UJ3>
- B 30 -
A O 1M * H VI ; '1A IM
Table B5(20 ) Analysis of variance of scores on Item 603 by test version with covariable MARKRTOT
* « La. «jl. 41 41M *3 3 c i 3* «n Z La. 'S CM CM s 4i 41O O • • • • •
« «Il *—» 4i 4(CO«li « 41cm cm i C Xi« ♦ CM CV x r r r <c «r 41La. vS cm m tr.* 41 • • m • • »—* 41TT rr rs
41 « CV CM CO 41
41 41 >- 41Z u i tn x> X i X ) X i <c CM
41 41 *4 c r CS CS CM CM M X J 41Lki <3 t T X i CM CM fü
41 « X 3 • • • • • • m <T 413 ro «-4UJ 4i CO 41
CJ * «< 41
3 4i 41
*<1 41 X 41
41 3 41La. PO *r m PSÛT 4r C- CM CM 41cm CM
<x 41 O- «H> 41 < 41
41 U. co iCi «r v£ vC <r a O «*o uj K N TO tn v-4U. 41 ZL ir, «r «c <c Xi PS •—* 41T < • • • • • • •
Z2 4T 3 ~ •«** w\ sr CM «c La. 41O T -o O■H co *” 41
CO 41 CO 4l— 41 CO 4Tco 41 -J 41
V 4i -J 41« MJ 41*
- B 31 -
GRAN
D 1 =
.2)
ADJU
STED
FO
RAD
JUST
ED FO
R IN
DEPE
NDEN
TSUN
ADJU
STED
IN
DEPE
NDEN
TS
♦ CO
VART
ATES
V aR I A
lti F
♦ CA
IFJP
UY
-I DE
V'N
FT*
D£V • N
PETA
Dt
V ' N
BETA
1 TEM
7u 1
HT VEftSiO.H
11 Tii
flAf
CKKT
i'jT
Table B5 (21 ) Analysis of variance of scores on Item 701 by test version with covarlable MARKRTOT
« k u . u . tn "O CM k k 2 COw 53 Q CM O * -
* k 2 U. G G N K G k k u_ 2O • • • • • U i
k * k k c ctn LU 3
k ♦ k * - U Jt n i n CO CL
* * a o* W— CO k — U*u . - n m O ^ c .
♦ k • • • • • k C . 2* s CM <r *-•
k k CO k
k k >- k2 U1 O ' 0 » r o i n if ) r o a c
* k a : no m o o - IT. CM **> _ J k oa - <2 r j G G *C CM CM Lfc_
k k Z IT • • • • • • • ■k k3 CM CM 3
«A* k C/5 2 k i L♦—
o k •k k CO
2 k k
< k z k C
k C kU_ rr 1*3 N
OL k o CM CM *-* kCM Ob
< k h- k
> k c k
k u . CO o * o G G * rs i n L i kCT a i -n :0 00 *-• sC ■C
u. k a CM (M kn < • • • • • • •
w k CM CM CM CM U. k/»
k co k
J? k CO k
k CO k
cO k <r k
> k k
- B 32 -
UNAD
JUST
ED
INDE
PEND
ENTS
+
CMVA
RIAT
ES
VAWl
AfUE
+
C A TF
V ¡1
UEV'
II
ETA
DEVN
BETA
Dt
'V'N
BE
TA
Table B5(22); Analysis of variance of scores on Item 702 by test version with covarlable MARKRTOT
Table B5(24): Two-way analysis of variance of scores on item 305 bytest version and gender with covariable MARKRTOT
u. z cs m cm i?: -r_ iC * « fv x X•-* CM CM cm n c ►— aJ4» X * * U. 7 ►-Z • LJ <■* * a z00 u. 2 a:«* »— _U <z z ry C*vin ir . m X 1.0Q. >z s IV TT CM m rr "O in * z iL.cJu. S'. X c* CM *o r. j c« z• • • • • • • • M < ~m it CM CM cn *
< »—♦ ♦
>- MZ a. X -O rv CT' ^ X Xi m 'y C0-c or X X - - S ' rr rr _ CM -j * z ►—< — ««« cm 'Z> •v t? CM CM3: z < ■* Luz z zc r 2T u a z
*— a .< ■K CT_■
<c C7*
z «# <r
•Ka_ •5T•r* m ro X O xZ CM CM »—» •« C<M CM u J
♦- ♦ >-CO< ye
zLi_ IT, vO O Z rv PV fV CM X rv u •** co sU X X r » 'C rj- m rv <
X — «-« X Pv *n -n n TT rv _* *~z.< zz _ — «—I ^ — ro rv Z *-0 z • y nx *
XCT
*►- «
*o >— occr sc ■*
xa- u. c «*-♦ > -O '
X *3 ( J .Z
>■ X < o
< <r X CJ zII z
Z rA. _o o X CO
JC 2 la . z _ - J z
—1 -> > > ■>x ~
z «2 •I . * - CM ■n TPz Jj<■ 2; 'V-
- B 35 -
Table B6(l): Two-way analysis of variance of scores on item 101 bytest version and performance tertile with covariable MARKRTOT
B37
Table B6(2): Two-way analysis of variance of scores on Item 102 bytest version and performance tertlle with covariable MA.RKRT0T --------------------- -—
B38
V
Table B6(3): Two-way analysis of variance of scores on item 103 bytest version and performance tertile with covariable MARKRTOT
ft it u_ — — •— x . x X sC X*-* ■ • J *r tv X >c X
ft i f 5 IT X X X-O “ ■ •
ft ft ►—X
ft ft— — X ■T- c cr C-s c
ft ft cr X «— —X X x . f\* — T rr -C
ft i f •C\t r j —*
ft ft — —
ft fta - >c r . «c «— — r ? >T'.
■n. ft < i J ? C X. r*“ Cv X X TJJ N* * c — r v —• f\.
ft ft i . ~r •:\i
•Aj ft IT.
*
- ft
ft
ft'a_ — — x r . e •c X
ft C.: — — A ir\ r v
< ■ft
■> f t
f t U. X £■ CY IV rv r«v X rI, -J r*. c L S i X X •C " X
ft ft *? rs —. •7 rt rv X*- -rc. ft ~ - C\ C\ r* — X.—■
ft
IT ft
- nrV- -
ft
ft
ft
f tfc c _ ft—• —♦•—• **■ft »— jC -ft a-
-U •f ~ —)ft *—■i < ft — *—1
■H~>— - *—ft •* <■ •—IX
>• —f •— —i■ft CL ►— ft .■v w *—
•—r < ■jy <1
ft f > *— ►-X 7* vJ u UJ T
4t ■ft •— _ _. *— CL*— . f *—» •—* _ • 1 w
« ft c X < r ►— •4►— £: li. 21 zc *—♦ zz
■ft ft U < J J >- —• < si —X — > ►— < •>• _J — * cr
ft ft — r. G. X ►—c c . < t >* u J o
ft ft cr u r Ow «JU ar
B39 -
Table B6(4): Twcr-way analysis of variance of scores on Item 104 bytest version and performance tertile with covariable MA.RKRT0T
k ★ u . u . — — s o X X3 X X r v C X r v
k * vL. 3 c\ r r cv —
C 3 •k k
cr
■ u k
T* ■3 3 X O' 0■* k O c X — X 'S? O
L l . IT .3 CV 3 O O Tk * • • • • • • • •
■ «—* M _k « -------------■
k *
~ ~ -vJ f v r v f v * - 3k k < i X f v — X r. V
_—i <T N IV •“ —k k
- •« i f l
tr
r k
< k
— k
a . X *3 Tw_ » ,
— k — — f-v
c k
> k
« II. CT N N •X — f v X X f v3 ___: - n r r 35 — _ ?» 0
k O V rv V r\j r . ~~ ,—l - r
k 3 3 — X—
k C3
t f l k
- k
k
V k
-
k
. r h- k
<r 3 c kf -* _
k V. ►— k .3
x .u Z t a*: _ Jk f— w c k »■— « —
—• •> *— V— —, —k k < *— Z
■>- 3 —
k _L k l_ —•— •¡r 'S z
• * » k -> *—
k k mJ *— 3 __3 *— T . u . «—► —« “ —a OJ __!
k k < t LT •— »X <T
UJ *— ^ -k. 1 : 3 r •—c 3
k k O Z z < JL. OJ >* Uj <-X 3 3 > »— < > - 1 M
k k ■ 3 > *-* T (X ►-
C? 3 <■ 1 X X i c?k k t/j LJ T rvj Li. o r »—
- B40 -
Table B6(5): Two-way analysis of variance of scores on item 201 bytest version and performance tertile with covariable MARKRTOT ------------ —
- B41 -
Table B6(6) Two-way analysis of variance of scores on Item 202 by test version and performance tertile with covariable MARKRTOT
Table B6(7): Two-way analysis of variance of scores on item 203 bytest version and performance tertlle with covariable MARKRTOT
B43
Table B6(8): Two-way analysis of variance of scores on item 204 bytest version and performance tertile with covariable MARKRTOT ~ ---------------
4C * u . ‘a . c r » - X X“•—1 — X >c •
■*» > x *■ • r K* *r- —: *5 “
4» ♦Ji
4c 4C— _ • r <%■ — X : ■/> T“
4* tr- '■ Oo a c —•X. sT5 S r o* rv»
HC 4T • • • • » • • •— * ^ C v — ^
4c 4C f\i (V
41 4r-7 j j IT ¡J- X X Si X, — _ _
r r — ■> .«#* «*■; V_ _* r •.? r\, ;m PV c v
4* _ •.11
Jl. 4c
4C
- 4*
< 4C
— 4»
■a. — —. a " *'* T v 1 C- a j ■C x -CL 4C c *— fV
r v Tv4f
> 4t
4c u . x c r ^ x r ^ O ' 7 r X^ .__ i N C4 S2 “ 0 4
L i. 4» ■X — — n r \ •?* T »T / rr- r~ <T
w 4C ~ ~ iT .T <\ — • - — . r X'" ? <»
* c r
<n 4»
- ■m
m *
>■ 4C
— • *
< . *
- 41~ ~T __ i ►— 4C
r . —• > 4 Vr c r X 4C
« >— U . <z « *— i——» *» *—
•« 4C <■ * - _ r> - —« •— a j
•** 4C c _ ' ♦ -—• •< •n -X
- « « ■« > ►- •—.O '.1 O "* 4 - ■ if "
«X . w — _ w . j l•— £ • —» T —• j J
« «4 * . 1 t ’,r - k— — X <»—» _ a - — 11 >—< ~
« 4t i - : ~L, — > - «L< <x H i - j— <•1 "> - J <
4C 4C > *—t ~ 2 . c r ►-< « X •j - i
4T « y j o 7" c \ u .
- B44 -
Table B6(9): Two-way analysis of variance of scores on Item 205 bytest version and performance tertile with covariable MARKRTOT -------------------
B45
Table B6(10): Two-way analysis of variance of scores on item 302 bytest version and performance tertlle with covariable MARKRTOT ~ ---
B46
Table B6 (11 ) Two-way analysis of variance of scores on Item 303 by test version and performance tertlle with covariable MARKRTOT "
B47
MTAI
Table B6(12): Two-way analysis of variance of scores on item 304 bytest version and performance tertile with covariable MARKRTOT
* * a. ul cx cx »** rx cr s.*—< — —• ?X - *7, ■X -C _
* •* *' U_ x. x rx fxi-T 77 • • • • • • • •
* -* *—‘•fi
■*r £ s* c X X 0
■* c c f\ X T X*r sC ir. x : — -
* • • • • • • • •c x — •
* ■*
* *X IT X X y .
* <■ Ti: cx cv x rv r « » — . X *— ci-: 1 <T ■c *T n c\ Cw Cv
* ~
* cr
■n
i. «
C *
— « t -4* cx n .
•* ~ « - C\.fX 'J
< *
> «♦r
M a. y x x - ^ rx r x X fx“ -a Csi r„ rx — • O ‘ .. _!• n c 7
it. 4t (V ry cx •*x »x rx V;
— * 7. ~ r—^ »X *-7; •7
- «
y ■«
> *
_ «
< *
•*—*• • ,*2- C •«
i— •—i .‘2■« 7 1/5 »— * ■« r U-
_/ _rT■* *— •a ■« •— *—■
— V -» — >—■* « •— X
>- ■ 7 —* •—-*c •7 ■« n.
—4 *7 <« ■# > •—
« j — -a T•* « o. •— — _ «— _•
-7 ' — ♦ — " —4 M—41 ■* <* X a . «7 *— •— < I T «-1
t j j f— 1 . j j 1 ’ * ~l
■* L J u . « Wi_ > - a . < r
< T . r— 'I ►—« <
■* * #— ♦ ■5“ X <r> *—
w < 1 X X J« * y < j T " c x '• x i X *—
- B48 -
Table B6(13) : Two-way analysis of variance of scores on item 305 bytest version and performance tertile with covariable MARKRTOT ~ ---------------
B49
nu ni
Table B6(15): Two~way analysis of variance of scores on item 405 bytest version and performance tertile with covariable MARKRTOT --------------------
- B 51 -
\
>
Table B6(16): Two-way analysis of variance of scores on Item 406 bytest version and performance tertile with covariable MARKRTOT
- B 52 -
Table B6(17): Two-way analysis of variance of scores on item 502 bytest version and performance fertile with covariable MARKRTOT
■¥ « u- rs rv 7 X c\ — — C\•—' Ow rv x . ZT -n X
* 41 a. O-' iT cc x IT- m(X ~ • • • • • • • •
-K 4C •—in
* *c »Vrr c\ r\
* *■_ C-L x ff X s rvu_ •— x V". x x
* ■» •c,
■*
•* •*- ’uJ Tv rv rv -O .- r
•1» ■* < a *z £ Cv c c Tv CxLx < C ®. — — 0« c\
•V. r .u. cr
w. *
— *
c *
- ■Hu. _ A/ fv -r
Zc ■* ~~ •— c\v
c *
> «
* u. co <\ c „ N* r CV. x c_ ~ o C S ' -J- *T CO C4 :* ~ *- rv •— X . Tv *—
.+T M ~ — rv X
.0 r "7M -
cr 4f- 4*V *>- M
— 4tc *X. «
v _<4 * . w r—■«
J? *—11—<•* r t . ►— 4r ~■* < ■K •— '——• > r— •— *—
* c •—j - *—«Jw
■* LL w—• -tt ■« > •— x.
_> - aJ -■* a. a- *— u_ J.- — w
►— w». —« •—4 —• a. —*« * < *—• CO ... «1
. v •—* cj w' CT *—* _■« 4t Q: < %±J >■ hfcs «i C?
:jl — cc "» p— L> _i *—* «5♦ « > •: w cO
x < 1 X a.. w-« ir. LJ ?• cv LLj 2-
- B53 -
Table B6(18): Twcr-way analysis of variance of scores on item 503 bytest version and performance tertlle with covariable MARKRTOT
- B54 -
Table B6(19): Two-way analysis of variance of scores on item 601 bytest version and performance tertlle with covariable MA5KRT0T — -------------
B 55
Table B6(20): Two-way analysis of variance of scores on Item 603 bytest version and performance fertile with covariable MARKRTOT
- B 56 -
Table B6(21): Two-way analysis of variance of scores on item 701 bytest version and performance fertile with covariable MARKRTOT ' ------------- “
* * U. lx — — K X X X X— Oj kT, X X C\#■* * n u . " , Jf cv x _ r r r :
.r • • • • • • • •* *—s .
M- - ^ J k ■n 'O« <5. c\ <\ _
a . X Xs V C*> _ „■* • • • • • • • •s ... — f\j C\JM. * ’-------* *
.r u j O' C* ■5 x r *T X; X■fc <T * »T> — x rr rr -c r : fV r .a - < rr ro X Cw fV' c\,♦ ■k i* _. • • • • • • • • • •
77 rs* cvu . S
u
- ♦
< *
*S . r \ ^ +• cv Xiac « cv
CV■«
> *
«* u_ s O' cr ? X c r . c\ XZ, -aJ -o o O T C •V hv •X Si* -C iT; — CV ■c ?v- «? • • • • • • • • • ••# — “ rv r v — ^ — s fV « V
•fc s .
S.
-
tr. •*
V •#
—c •r
- ►— «—• *?
< c . __ *— *—4
it tr •— « z ..-U * ' .1. 2 n _ j•« *— <3 *— '•> *“ •— — __
■*» ■* <i *— t l— 1 r— _j
« ►- a r.: ;■ v——*• < 0
« £ « ,> *— ►—-O “7 z ) r «.» ~
kk. -k. •“ *— ^•— •«. ik. •—• — 7 »—* ■+J .
* ■* <■ x ^ s > - Sj .2 c*— 1 J i ~2 Z. 22 •—* 7-
« o ^ <3 L+j >x. >■ ul < 22H < r '. T *— < ■> —i r—4
■* * “ > ►— 7 IS »—22 < « >< uJ
« iS> CJ 3T Ow ixJ a : *—
- B 57 -
Table B6 (22 ):___ Two-way analysis of variance of scores on Item 702 bytest version and performance terHIp w-M-h rma r i a M o MARKRTOT -------------------------- -— --- ----
- B 58 -
Table B6(23): Two-way analysis of variance of scores on item 703 bytest version and performance fertile with covariable tlARKRTOT ------------
B59
PROBLEM-SOLVING
IN O-LEVEL CHEMISTRY
Instructions :
1. This test consists of questions which require a short answer to be written in the space provided on the question paper.
2. No mathematical tables, slide rules or calculators will be needed.
3. A few questions may relate to topics or substances with which you are not expected to be familiar. In such questions the necessary data have been provided and you are being asked to think clearly in a new situation.
4. Please write your name, form and sex (M or F) in the spaces provided.
NAME (block letters please)
PLEASE DO NOT TURN OVER UNTIL YOU A R E TOLD TO DO SO
(for office use only)M S F 0/1 V T , ,
Department of Education, University of Keele.
D.Slimming
January 1980
INSTRUCTIONS FOR SELF-REPORTING FORM
In this test we are interested not only in your answers, but also in how you obtained them. Described below are seven ways in which pupils who helped with this research last year, answered questions. Read them carefully and make sure you understand them. There will be a chance for discussion before you start the test.
(i ) The answer is remembered:SM = SIMPLE MEMORY - the answer is simply remembered.CM - COMPLEX MEMORY - different parts of the answer have to be
remembered separately and brought together; or the answer may be remembered only step-by-step or by a round-about route.
(ii) The answer is worked out:SR = SIMPLE RULE - the question is recognised as an example of a
simple rule which leads straight to the answer; an example of such a rule might be acid + metal ----- ► hydrogen.
Ap - APPLICATION - the answer is worked out by applying chemicalprinciples or knowledge (e.g. in working out how the yield of a reaction will be affected by an increase in pressure).
Cp — COMPARISON - the answer is obtained by making a comparison (or analogy) with an example which is already known.
(iii) The answer is guessed or omitted:BG = BLIND GUESS - no chemical principles or knowledge are used.CG = CALCULATED GUESS - a guess based on partial chemical knowledge.0 = OMIT - no answer is given.
2. As soon as you have answered each part-question, you are asked to complete a table like the one shown below:
3. First fill in the appropriate question number, then tick the box which best describes the way you obtained your answer.
4. If you tried a different strategy first but it did not work out you should mark the corresponding box with a cross (e.g. in the example given above the pupil tried application first, then guessed when he got stuck).
5. Under the boxes you should give, in note form, further details about how you obtained your answer. There is a separate space to note any difficulties you may have encountered.
6. Finally you are asked to indicate how confident you are about your answer by writing a number in the small box on the right, using the code:
4 = sure its OK 3 = probably OK 2 = 50/50 1 = probably wrong
Question 7 j b U ) I SM [ CM I SR I | Cp | BG I I 5~| fTl
1 PLEASE DO NOT TURN OVER UNTIL TOLD TO DO SO
ANSWER ALL QUESTIONS. PLEASE DO NOT WRITE IN THE MARGIN.
1. A dilute solution of sulphuric acid is electrolysed between platinum electrodes.
(a) (i) State the name o f the product formed at the anode ............
(ii) State the name of the product formed at the cathode ............
(b) During the early part of the electrolysis, the amount of product that collects at the anode is always somewhat less than that calculated. Suggest a reason for the low yield at the anode.
(c) What would be the effect on the electrolysis of a limited increase in the concentration of the solution (at constant current)?
(d) Explain how the method of conduction of an electric current through dilute sulphuric acid differs from that through a copper wire.
Question I SM f CM | SR | Ap | Cp | bg I CG □Strateqy/workino:
Any difficulties:
fluestion------------ [ SM I CM I SR | Ap I Cp 1 BG I CgTT~I |------[Strateav/workina:
Any difficulties:
&UeStion------------ 1 SM I CM | SR | Ap | Cp | BG I rë~f~Ô~1 |------1Strateav/workina:
Any difficulties:
Question | SM | CM | SR I Ap | Cp I BG I CG I O 1 |------1Strateav/workina:
Any difficulties:
^ estion______ ÇSM | CM | SR | Ap 1 Cp | BG |"'cg' 1 O I |------[St rateav/workina:
A n y difficulties:
3/5/7/9/l 1/13/15
2. The table below gives the number of electrons, and the mass numbers, of six neutral atoms labelled E to X.
E G J L M X
Number of electrons 6 9 14 16 16 19
Mass number 12 19 28 30 32 40
Use the letter at the top of a column to represent the element or one atom of the element.
(a) Which two different elements are in the same group of the periodic table?
(b) Which atoms, if any, are isotopes?
(c) Which element is the best reducing agent?
(d) Which element is a halogen?
(e) Derive a formula for the compound formed when X reacts with M.
Question------- I SM f CM | SR I Ap | Çp | BG I CG I O 1 | |Strateqy/workina:
Any difficulties:
Question------- ( SM | CM I SR [ Ap I Çp | BG I "cG I O I |---1Strateav/workina:
Any difficulties:
------- I SM | CM | SR | Ap | CP | BG I CG I O 1 [---1Strateqy/working:
I.
Any difficulties
Question_______
Strategy/working
Any difficulties
Question_______
Strateqy/workinq:
Any difficulties:
I SM | CM | SR | Ap | Cp | BG I CG I O I |---1
LSM I CM I SR I Ap I Çp I BG I OG I O I |---1
3/5/7/9/11/13/15
3. (a) Define oxidation in terms of changes at the atomic level.
(b) In each of the following equations underline the substance which is being oxidised.
3+ 2 + +(i ) Fe + H -------- *- Fe + H
2 +(ii) Cu + Br2 ---------* • Cu + 2Br
(c) Give the names of the industrial processes which involve the following
(i) the catalytic oxidation of sulphur(XV) oxide to sulphur(VI) oxide (using a catalyst of platinum or vanadium(V) oxide).
(ii) the catalytic reduction of nitrogen to ammonia (using a catalyst of finely divided iron with promotors).
Question_______Strategy/working:
SM [ C M | SR | Ap 1 Cp 1 BG I CG~ □
Any difficulties:
gestion_______ f SM I CM I SR | Ap I Cp I BG I CG I O I |------1Strategv/workino:
Any difficulties:
Question_______ f SM I CM | SR | Ap I Cp | BG I OG~T~5~l |---1Strategy/workino:
Any difficulties:
Question_______ I SM | CM 1 SR [ Ap | Cp | BG 1"cG I O 1 |------1Strateav/working:
Any difficulties:
Question j_.SM I CM | SR I Ap I Cp I BG I GG~I O 1 |------1Strategy/workina:
Any difficulties:
3/5/7/9/11/13/15
4. (a) Briefly describe how, by means of a chemical test, you would show that an aqueous solution contains a reducing agent. State what you would do, and what you would observe if the test was successful.
Procedure .....................................................
Observations
(b) At which electrode, if either, are ions reduced during electrolysis?
(c) A simple cell is formed by dipping strips of zinc and copper into an aqueous solution of an electrolyte. When a small current is drawn from the cell
(i) which strip of metal will be the positive terminal?
(1 1) what chemical change takes place at the surface of the zinc?
(in) explain why bubbles of a gas start to collect on the surface of the copper strip.
Question i SM [ C M | SR [ A p | rP I Rr. | r n | n [ □Strateqy/working:
Any difficulties:
Question 1 SM | CM [ SR [ Ap | Cp | rt, | rr. T Ô J □Strateqy/working:
Any difficulties:
Question i SM 1 CM | SR ( Ap [ Cp | Rn | rn | n | □Strateqy/workinq:
Any difficulties:
Question | SM I CM I SR I A d I Co I BG I CG I O I □Strateqv/workinq :
Any difficulties:
Question______ | SM I CM I SR 1 Ap I Cp | BG I OG I O j | [Strateqv/workino:
Any difficulties:
3/5/7/9/11/13/15
5. (a) Give the formula of ammonium carbonate.
(b) Describe how you would show by experiment that a colourless liquid is water.
(c) The formula of urea is (NH^JgCO and it is a covalent compound, to draw its full structural formula.
Try
Question______ I SM [ CM | SR I Ap I Cp 1 BG I CG 1 O 1 | |Strateqy/workina:
Any difficulties:
Q,M.estr*ron------ I SM I CM I SR I Ap 1 Cp I BG I CG T Ô 3 □Strateqy/workina:
Any difficulties:
Question I SM | CM | SR I Ap | Cp I BG I OG I O 1 ( |Strateqy/workina:
Any difficulties;
Question I SM I CM I SR I Ap I Cp I BG I CG I O I □Strateav/workina:
Any difficulties;
Question______ | SM I CM I SR I Ap | Cp | BG I CG I Ô I | |Strateov/workina:
Any difficulties:
3/5/7/9/11/13/15
6. Give the name of the gas evolved in each of the following reactions:
(a) manganese(IV) oxide reacts with hydrochloric acid.
Name of gas ....................
(b) ammonium chloride is heated with calcium hydroxide.
Name of gas ....................
(c) copper reacts with sulphuric acid.
Name of gas .....................
Question------ i.SM f CM I SR I A p I Cd I BG I'c g 1 O I |---1Strateqy/working:
Any difficulties:
ftHg.§.tion------ i S M I CM | SR | Ap I Cp I BG I C G ~ T o ~ l QStrateov/working:
Any difficulties:
£ u?stion______ f SM | CM | SR | A d I Co I BG I OG I 0 1 QStrateqy/workinq:
Any difficulties:
Q uestion I SM | CM | SR [ Ap I CD I BG I CG I 0 I |--- 1Strategy/workinq:
Any difficulties:
Question______ j SM [ CM 1 SR I Ap | Cp I BG I CG I O ~| |--- 1S t ra tegy/workina:
Any difficulties:
3/5/7/9/11/13/15
7. (a) Soap is manufactured by boiling fats (e.g. esters of oleic, palmiticand stearic acids) with sodium hydroxide solution. Give the chemical
name of a soap.
(b) Explain briefly why soap will not lather well with hard water. (Refer to the role of dissolved calcium salts in hard water).
(c) Describe how you would distinguish, by a chemical test, between sodium hydrogencarbonate (NaHCO^) and hydrated sodium carbonate ( N a 2CO3 . 1 0 H 2 O ) .
Question_______ | SM f CM | SR | Ap I Cp 1 BG | CG I Q~| | |Strateov/working:
Any difficulties:
Question I SM | CM | SR | Ap | Cp [ n r, | rn TÔJ □Strategy/working:
Any difficulties:
Question I SM | CM | SR | Ap 1 cP 1 Rn [ nn | n □ □Strateqy/workinq:
Any difficulties:
Question SM I CM I SR | Ap | Co I BG I CG I O I □Strategy/working :
Any difficulties:
Question_______ I SM 1 CM I SR I Ap | Cp | BG I OG | O I | |Strateov/workina :
Any difficulties:
3/5/7/9/11/13/15
PROBLEM-SOLVING
IN O-LEVEL CHEMISTRY
Instructions :
1. This test consists of questions which require a short answer to be written in the space provided on the question paper.2. No mathematical tables, slide rules or calculators will be needed.3. A few questions may relate to topics or substances with which you are not expected to be familiar. In such questions the necessary data have been provided and you are being asked to think clearly in a new situation.4. Please write your name, form and sex (M or F) in the spaces provided.
NAME (block letters please)
FORM .............. SEX
PLEASE DO NOT TURN OVER UNTIL YOU ARE TOLD TO DO SO
(for office use only)M S F 0/1 V T • • .
Department of Education, D.SlimmingUniversity of Keele January 1980
INSTRUCTIONS FOR SELF-REPORTING FORM
In this test we are interested not only in your answers, but also in how you obtained them. Described below are seven ways in which pupils who helped with this research last year, answered questions. Read them carefully and make sure you understand them. There will be a chance for discussion before you start the test.
(i) The answer is remembered:SM = SIMPLE MEMORY - the answer is simply remembered.CM = COMPLEX MEMORY - different parts of the answer have to be
remembered separately and brought together; or the answer may be remembered only step-by-step or by a round-about route.
(ii) The answer is worked out:SR = SIMPLE RULE - the question is recognised as an example of a
simple rule which leads straight to the answer; an example of such a rule might be acid + metal ---- ► hydrogen.
Ap = APPLICATION - the answer is worked out by applying chemicalprinciples or knowledge (e.g. in working out how the yield of a reaction will be affected by an increase in pressure).
Cp = COMPARISON - the answer is obtained by making a comparison (or analogy) with an example which is already known.
(iii) The answer is guessed or omitted:BG = BLIND GUESS - no chemical principles or knowledge are used.CG = CALCULATED GUESS - a guess based on partial chemical knowledge.O = OMIT - no answer is given.
2. As soon as you have answered each part-question, you are asked to complete a table like the one shown below:
Question 7 (¿ > )Ç i) I SM I CM I SR I A i I C p I BG I ^5 I O 1 I -2- 1
Strateqy/workings : ^ ^
f a u / f ' s C j x d -A) c o c o a .
Any difficulties: C o - c c ^ o i ^ t <r 4-#^ ¿j'/A cÂ
3. First fill in the appropriate question number, then tick the box which best describes the way you obtained your answer.
4. If you tried a different strategy first but it did not work out you should mark the corresponding box with a cross (e.g. in the example given above the pupil tried application first, then guessed when he got stuck).
5. Under the boxes you should give, in note form, further details about how you obtained your answer. There is a separate space to note any difficulties you may have encountered.
6. Finally you are asked to indicate how confident you are about your answer by writing a number in the small box on the right, using the code:
4 = sure its OK 3 = probably OK 2 = 50/50 1 = probably wrong
1 PLEASE DO NOT TURN OVER UNTIL TOLD TO DO SO
ANSWER ALL QUESTIONS. PLEASE DO NOT WRITE IN THE MARGINS.
1. A dilute solution of sulphuric acid is electrolysed between platinum electrodes.'
(a) (i) State the name of the product formed at the anode ..........
(ii) State the name of the product formed at the cathode ..........
(b) During the early part of the electrolysis, the amount of product that collects at the anode is always somewhat less than that calculated. Suggest a reason for the low yield at the anode.
(c) What would be the effect on the electrolysis of a limited increase in the concentration of the solution (at constant current)?
(d) Explain how the method of conduction of an electric current through dilute sulphuric acid differs from that through a copper wire.
Question_____ I SM [ CM I SR I Ap I Cp 1 BG I CG 1 Q IStrateqy/workinq:
Any difficulties:
Question I SM I CM f SR | Ap | Cp | ht, [ fr. r a □Strateov/workino:
Any difficulties:
Question_____ | SM I CM I SR I Ap | Cp | BG I OG I O I | |Strateqy/workinq:
Any difficulties:
Question_____ I SM I CM I SR I Ap I Cp I BG I CG 1 O IStrategy/workinq:
Any difficulties:
Question_______ I SM I CM I SR I Ap I Cp I BG I OG inn □Strateov/workinq:
Any difficulties:
3 / 5 / 7 / 9 / 1 1 / 1 3 / 1 5
2. The table below gives the number of electrons present in six neutral atoms labelled E to X.
E G J L M X
Number of electrons 6 9 14 16 16 19
Use the letter at the top of a column to represent the element or one atom of the element.
(a) Which two elements are in the same group of the periodic table?
(b) Which atoms, if any, are isotopes? ............
(c) Which element is the best reducing agent? ............
(d) Which element is a halogen? ............
(e) Derive a formula for the compound formed when X reacts with M.
Question_____ I SM i CM I SR I Ap I Cp I BG I CG I O 1 | |Strategy/working:
Any difficulties:
Question____Strategy/working:
I SM | CM f SR | Ap | Cp | BG I CG | O I □
Any difficulties:
Question I SM I CM I SR I Ao I Co I BG I GG I O □ □Strategy/working:
Any difficulties:
Question_____ | SM i CM I SR [ Ap [ Cp | BG | CG I O I □Strategy/working:
Any difficulties:
Question I SM I CM I SR I Ap | Cp I BG I CG~ □Strategy/working:
Any difficulties:
3/5/7/9/11/13/15
3. (a) Define oxidation in terms of changes at the atomic level.
(b) Only two of the following changes are oxidation. Underline the two
substances which are beinq oxidised.
(i) Fe3+(aq ) -------- ► Fe (aq) (Ü) H(g) --H+ (aq)
(iii) Cu(s) -------- ► Cu2+(s) (iv) Br2 (1 ) — w 2Br“ (s)
(c) Give the names of the industrial processes which involve the following:
(i) the catalytic oxidation of sulphur(IV) oxide to sulphur(VI) oxide in a stainless steel vessel.
(ii) the catalytic reduction of nitrogen to ammonia in the gaseous phase.
Question ! SM \ CM ! SR 1 A d 1 Co 1 BG 1 CG 1 O 1 Strategy/working:
□
Anv difficulties:
Question | SM I CM f SR I Ap | Co 1 BG 1 CG 1 O 1 Strateqy/workinq:
□
Anv difficulties:
. Question 1 SM 1 CM I SR | A d 1 Cp 1 BG 1 Π1 O 1 Strateqy/workinq:
□
Anv difficulties:
Question | SM I CM 1 SR I Ap I Cp 1 BG 1 CG 1 O 1 • Strateov/workinq:
□
Anv difficulties:
Question 1 SM 1 CM 1 SR 1 Ap 1 CD 1 BG 1 CG 1 O 1 S t ra t eqv/workinq:
□
Anv difficulties:
3/5/7/9/11/13/15
4. (a) Briefly describe how, by means of a chemical test, you would show that an aqueous solution contains a reducing agent. State what you would do, and what you would observe if the test was successful.
Procedure ..................................................................
Observât ions
(b) At which electrode, if either, are ions reduced during electrolysis?
(c) A simple cell is formed by dipping strips of zinc and copper into an aqueous solution of an electrolyte. A small current is drawn from the cell. (The order of metals in the electrochemical series is: Na, Mg, Zn, Fe, Pb, (H), Cu, A g ).
(i) Which strip of metal will be the positive terminal? ..............
(ii) What chemical change takes place at the surface of the zinc?
(iii) If the electrolyte is sodium chloride solution, explain why bubbles of a gas start to collect on the surface of the copper strip.
Question ( S M [ CM 1 SR I A d 1 Co 1 BG 1 CG 1 O 1 Strateav/workinq:
□
Anv difficulties:
Question I SM I CM [ SR I Ap I Cd 1 BG I CG 1 O 1 Strateav/workinq:
□
Anv difficulties:
Question 1 SM 1 CM I SR I Ap | Cp 1 BG 1 CG 1 O 1 Strateqy/workinq:
□
Anv difficulties:
Question 1 SM 1 CM I SR 1 Ap I Cp I BG 1 CG 1 0 1 Strateav/workinq:
□
Anv difficulties:
Question 1 SM 1 CM 1 SR 1 Ap 1 Cp 1 BG 1 OG 1 O 1 Strateav/workinq:
□
Anv difficulties:
3/5/7/9/11/13/15
IIII5. (a) Give the formula of ammonium carbonate. .............
(b) Describe how you would show by experiment that a colourless liquid :is water.
(c) The formula for urea is to draw its full structural
N„H CO and it is a covalent compound. Try 2 4formula.
lOB
Question_______ | SM [ CM I SR I Ap I Cp I BG I CG I O I I 1Strategy/working:
Any difficulties:
Question I SM I CM f SR I A d | Cp | RG | CG T S D □Strategy/working:
Any difficulties:
Question_______ | SM I CM I SR I Ap [ Cp | BG I OG I O 1 I IStrategy/working:
Any difficulties:
Question______ | SM 1 CM I SR I Ap I Cp I BG | CG I O I I IStrategy/working:
Any difficulties:
Question I SM CM SR Ap I Cp I BG I OG I O □Strateov/working:
Any difficulties:
3/5/7/9/11/13/15
6. Give the name of the gas evo lved in each of the following reactions
(a) manganese(IV) oxide oxidises concentrated hydrochloric acid
Name of gas ..............................
(b) ammonium chloride is heated with calcium hydroxide.
Name of gas ..............................
(c) copper is oxidised by concentrated sulphuric acid.
Name of gas ..............................
Question 1 SM t CM 1 SR 1 Ap 1 Cd 1 BG 1 CG 1 O Strateqy/workinq:
□
Any difficulties:
Question 1 SM 1 CM f SR I A d I Co 1 BG 1 CG 1 O 1 St rateav/workinq :
□
Anv difficulties:
Question 1 SM 1 CM ! SR 1 A d 1 Co 1 BG 1 OG 1 O 1 Strateqy/workinq :
□
Anv difficulties:
Question | SM 1 CM 1 SR 1 A d 1 Cd 1 BG | CG I O I Strategy/workinq:
□
Any difficulties:
Question 1 SM 1 CM 1 SR 1 A d 1 Cp I BG 1 OG 1 O I S t ra t eav/workinq :
□
Anv difficulties:
3/5/7/9/11/13/15
7. (a) Give the chemical name of a soap.
(b) Explain briefly why soap will not lather well in hard water.
(c) Describe how you would distinguish, by a chemical test, between sodium hydrogencarbonate (NaHCC>3 ) and hydrated sodium carbonate
(Na2CO3 .10H2O).
Question 1 SM t CM 1 SR 1 A d 1 C d 1 BG 1 CG 1 O 1 Strateqy/workinq:
□
Anv difficulties:
Question 1 SM I CM [ SR | Ap | Cp I BG 1 CG 1 O 1 Strateov/workinq:
□
Anv difficulties:
Question 1 SM 1 CM 1 SR 1 A d 1 Cd 1 BG 1 CG 1 O ! Strateov/workino:
□
Anv difficulties:
Question 1 SM 1 CM 1 SR 1 Ap | Cp I BG | CG I O I Strateov/workinq:
□
Anv difficulties:
Question | SM 1 CM 1 SR 1 Ap I Cp 1 BG 1 OG _[ O — | Strateov/workinq:
□
Anv difficulties:
3/5/7/9/11/13/15
PROBLEM-SOLVING
IN O-LEVEL CHEMISTRY
Instructions :
1. This test consists of questions which require a short answer to be written in the space provided on the question paper.
2. No mathematical tables, slide rules or calculators will be needed.
3. A few questions may relate to topics or substances with which you are not expected to be familiar. In such questions the necessary data have been provided and you are being asked to think clearly in a new situation.
4. Please write your name, form and sex (M or F) in the spaces provided.
NAME (block letters please)
FORM .................. SEX
PLEASE IX) NOT TURN OVER UNTIL YOU ARE TOLD TO DO SO
(for office use only)
M S F 0/1 V T • • •
Department of Education,
University of Keele.
D.Slimming
January 1980
INSTRUCTIONS FOR SELF-REPORTING FORM
In this test we are interested not only in your answers, but also in how you obtained them. Described below are seven ways in which pupils who helped with this research last year, answered questions. Read them carefully and make sure you understand them. There will be a chance for discussion before you start the test.
(i ) The answer is remembered:SM = SIMPLE MEMORY - the answer is simply remembered.CM = COMPLEX MEMORY - different parts of the answer have to be
remembered separately and brought together; or the answer may be remembered only step-by-step or by a round-about route.
(ii) The answer is worked ou t ;SR = SIMPLE RULE - the question is recognised as an example of a
simple rule which leads straight to the answer; an example of such a rule might be acid + metal 1 ---- * • hydrogen.
Ap = APPLICATION - the answer is worked out by applying chemical j principles or knowledge (e.g. in working out how the yield of
a reaction will be affected by an increase in pressure).Cp = COMPARISON - the answer is obtained by making a comparison
(or analogy) with an example which is already known.
(iii) The answer is guessed or omitted:BG = BLIND GUESS - no chemical principles or knowledge are used.CG = CALCULATED GUESS - a guess based on partial chemical knowledge.O = OMIT - no answer is given.
2. As soon as you have answered each part-question, you are asked to complete a table like the one shown below:
Question 7 ç l ) d ) | SM I CM I SR I £ 6 I Cp I BG I I O I I 2 - I
S trategy/workings: ^ ^ ^ a U f e
b u / " ^ Û c / -/© ¿ ¿ ~ C O O -o .
Any difficulties: ¿Vco/iXiv. 1 1~ u f U * . c-A
3. First fill in the appropriate question number, then tick the box which best describes the way you obtained your answer.
4. If you tried a different strategy first but it did not work out you should mark the corresponding box with a cross (e.g. in the example given above the pupil tried application first, then guessed when he got stuck).
5. Under the boxes you should give, in note form, further details about how you obtained your answer. There is a separate space to note any difficulties you may have encountered.
6. Finally you are asked to indicate how confident you are about your answer by writing a number in the small box on the right, using the code:
4 = sure its OK 3 = probably OK 2 = 50/50 1 = probably wrong
1 PLEASE DO NOT TURN OVER UNTIL TOLD TO DO SO A
ANSWER ALL QUESTIONS. PLEASE DO NOT WRITE IN THE MARGINS.
il A dilute solution of sulphuric acid is electrolysed.I
(a) (i) State the name of the product formed at the anode ...........
(ii) State the name of the product formed at the cathode ...........
(b) During this electrolysis the amount of product that collects at the anode is always somewhat less than that calculated. Suggest a reason for the low yield at the anode.
(c) What would be the effect on the electrolysis of an increase in the concentration of the solution (at constant current)?
(d) Explain how the method of conduction of an electric current through dilute sulphuric acid differs from that through a copper wire.
Question______ I SM f CM I SR I Ap I Çp | BG I CG I O I | IStrategy/working :
Any difficulties:
Question I SM 1 CM I SR | Ap [ Cp | RG | ffi TSJ □Strateav/working:
Any difficulties:
Question______ | SM | CM | SR I Ap I Cp I BG I OG I Q~| | |Strategy/working:
Any difficulties:
Question | SM | c m | SB | A P | rr | nr. [ m | n | CZ3Strateov/working:
Any difficulties:
Question______ I SM I CM I SR I Ap I Cp I BG I OG I O IStrategy/workino:
Any difficulties:
□
3 / 5 / 7 / 9 / 1 1 / 1 3 / 1 5
2 . The table below gives the number of electrons present in six neutral atoms labelled E to X, together with the formulae of their compounds with familiar elements.
E G J L M X
Number of electrons 6 9 14 16 16 19
Formulae of compounds e c i 4 NaG J°2 CL2 Na2M XC1
Use the letter at the top of a column to represent the element or one atom of the element.
(a) Which two different elements are in the same group of the periodic table?
(b) Which atoms, if any, are isotopes? .....................
(c) Which element is the best reducing agent? .....................
(d) Which element is a halogen? .....................
(e) Derive a formula for the compound formed when X reacts with M.
4C
Question_______ I SM [ CH I SR I Ap | Cp 1 BG I CG 1 O I I iStrateav/workinq:
Any difficulties:
Question_______ I SM I CM [ SR I Ap I Cp 1 BG I CG I O I □Strateqy/workinq:
Any difficulties:
Question_______ I SM I CM I SR I Ap | Cp | BG I OG I O I I IStrateqy/workinq:
Any difficulties;
Question_______ | SM I CM I SR I Ap I Cp I BG I CG I O 1 □Strateav/workinq:
Any difficulties:
Question_______ I SM I CM I SR I Ap I Cp I BG I 03 I O I I IStrateqy/workina:
Any difficulties;
3/5/7/9/11/13/15
3. (a) Define oxidation in terms of changes at the atomic level.
(b) Only two of the following changes are oxidation. Underline the two substances which are being oxidised.
(i) Fe
(iii) Cu
Fe2+
Cu2+
(ii) H
(iv) Br„ 2Br
(c) Give the names of the industrial processes which involve the following
(i) the catalytic oxidation of sulphur(IV) oxide to sulphur(VI ) oxide.
(ii) the catalytic reduction of nitrogen to ammonia.
6C
Question I SM f cM I SB | Ap | Cp | Rfi [ cn | n □ □Strategy/working:
Any difficulties:
Question______ I SM | CM [ SR I Ap I Cp | BG I CG I O I [ |Strategy/working:
Any difficulties:
Question I SM I CM I SR | Ap | Cp | RG | n r. | n □ □
Strategy/workino:
Any difficulties;
Question |~ SM | CM | SB [ A p | Cp | R f i | m | n □ □
Strateov/workino:
Any difficulties:
Question_____ I SM I CM I SR I Ap I Cp I BG I OG I O 1 | [Strateov/working:
Any difficulties;
3/5/7/9/11/13/15
4. (a) Briefly describe how, by means of a chemical test, you would show that an aqueous solution contains a reducing agent. State what you would do, and what you would observe if the test was successful.
Procedure ..................................................................
Observations
(b) At which electrode, if either, are ions reduced during electrolysis?
(c) A simple cell is formed by dipping strips of zinc and copper into an aqueous solution of sodium chloride as electrolyte. When a small current is drawn from the cell
(i) which strip of metal will be the positive terminal? .................
(ii) what chemical change takes place at the surface of the zinc?
(iii) explain why bubbles of a gas start to collect on the surface of the copper strip.
Question______ I SH f CM 1 SR 1 Ap I Cp I BG I CG I O I | 1Strateav/working:
Any difficulties:
Question I SM I CM F SR I Âd [ Cp | BG | CG T U □Strateqy/workinq:
Any difficulties:
Question I SM I CM I SR ! Ap | Cn I BG | CG T U □Strateqy/workinq:
Any difficulties:
Question______ I SM I CM I SR I Ap I Cp I BG I CG I O I | )Strateov/workino:
Any difficulties:
Question______ | SM I CM I SR I Ap I Cp 1 BG 1 OG I O I | |Strateov/workina:
Any difficulties:
3/5/7/9/11/13/i S A
5. (a) Give the formula of ammonium carbonate.
(b) Describe how you would show by experiment that a colourless liquid
is water only.
(c) The formula for urea is (NH2 )2CO and it is a covalent compound. Try to draw its full structural formula. (Nitrogen normally has a valency of three in simple covalent compounds).
Quest: I SM \ CM I SR I Ap I Cp I BG I CG □Strateqy/workinq:
Any difficulties:
Question I SM I CM f SR I A d | Cp | BG [ CG | O | □Strateqy/working:
Any difficulties:
Question_______ I SM I CM I SR I Ap | Cp | BG I OG I O I [ |Strateqy/workinq:
Any difficulties:
□Question I SM I CM I SR 1 Ap I Cp 1 BG I CG 1 O 1Strateov/workinq:
Any difficulties;
Question_______ I SM I CM I SR I Ap I Cp I BG I OG I O I | |Strategy/workino:
Any difficulties:
3 / 5 / 7 / 9 / 1 1 / 1 3 / 1 5 %
6. Give the name of the gas evolved in each of the following reactions
(a) manganese(IV) oxide reacts with concentrated hydrochloric acid.
Name of gas ......................................
(b) ammonium chloride is heated with calcium hydroxide.
Name of gas ......................................
(c) copper reacts with concentrated sulphuric acid.
Name of gas
Question______ | SM f CM i SR I Ap I Çp I BG I CG 1 O 1Strateqy/workinq:
Any difficulties:
Question ! SM I CM f SR | Ap ( Cp | Rn | crT u n □Strateqy/workinq:
Any difficulties:
Question_______ I SM I CM I SR I Ap I Cp | BG I OG I O I | |Strateqy/workinq:
Any difficulties;
Question I SM I CM I SR I A d I Cd I RG I CG I O I □Strateov/working:
Any difficulties:
Question______ I SM I CM I SR 1 Ap I Cp I BG I CXÎ I O I | 1Strateov/workinq:
Any difficulties:
3/5/7/9/ii/i3/15 A
7. (a) Give the chemical name of a soap. .........................
(b) Explain briefly why soap will not lather well with hard water
(c) Describe how you would distinguish, by a chemical test, between sodium hydrogencarbonate and hydrated sodium carbonate.
Question______Strategy/working :
I SM [ CM | SR | Ap | Cp | BG I CG □
Any difficulties:
Question I SM I CM f SR I A d | Co I BG I CG H D □Strategy/working:
Any difficulties;
Question_______ | SM I CM I SR I Ap | Cp 1 BG I CG I O I I IStrategy/working:
Any difficulties:
Question______ | SM I CM I SR I Ap I Cp I BG I CG n = o □Strateov/working:
Any difficulties:
Question_______ I SM 1 CM I SR I Ap I Cp I BG I CG I O i I 1Strategy/workino:
Any difficulties;
5/7/ 9/11/13/15
PROBLEM-SOLVING
IN O-LEVEL CHEMISTRY
I ns t ruct ions :
1 . This test consists of questions which require a short answer to be written in the space provided on the question paper.
2. No mathematical tables, slide rules or calculators will be needed.
3. A few questions may relate to topics or substances with which you are not expected to be familiar. In such questions the necessary data have been provided and you are being asked to think clearly in a new situation.
4. Please write your name, form and sex (M or F) in the spaces provided.
NAME (block letters please)
FORM SEX
PLEASE DO NOT TURN OVER UNTIL YOU ARE TOLD TO DO SO
(for office use only)
M S F 0/1 V T • . •
D e p a r t m e n t of Education, D. Slimming
U n i v e r s i t y o f K e e l e . January 1980
INSTRUCTIONS FOR SELF-REPORTING FORM
In this test we are interested not only in your answers, but also in how you obtained them. Described below are seven ways in which pupils who helped with this research last year, answered questions. Read them carefully and make sure you understand them. There will be a chance for discussion before you start the test.
(i) The answer is remembered:SM = SIMPLE MEMORY - the answer is simply remembered.CM = COMPLEX MEMORY - different parts of the answer have to be
remembered separately and brought together; or the answer may be remembered only step-by-step or by a round-about route.
(ii) The answer is worked out:SR = SIMPLE RULE - the question is recognised as an example of a
simple rule which leads straight to the answer; an example of such a rule might be acid + metal ----- *■ hydrogen.
Ap = APPLICATION - the answer is worked out by applying chemicalprinciples or knowledge (e.g. in working out how the yield of a reaction will be affected by an increase in pressure).
Cp = COMPARISON - the answer is obtained by making a comparison (or analogy) with an example which is already known.
(iii) The answer is guessed or omitted:BG = BLIND GUESS - no chemical principles or knowledge are used.CG = CALCULATED GUESS - a guess based on partial chemical knowledge.0 = OMIT - no answer is given.
2. As soon as you have answered each part-question, you are asked to complete a table like the one shown below:
Question ) [ SM I CM I SR I £ i> \ Cp I BG I I O
Str.ateqy/workinqs: ^ ^ ^
b u J ' -/o C^~ CO<X,o ,
Any difficulties: C o -< -c /o b ~ < t
3. First fill in the appropriate question number, then tick the box which best describes the way you obtained your answer.
4. if you tried a different strategy first but it did not work out you should mark the corresponding box with a cross (e.g. in the example given above the pupil tried application first, then guessed when he got stuck).
5. Under the boxes you should give, in note form, further details about how you obtained your answer. There is a separate space to note any difficulties you may have encountered.
6. Finally you are asked to indicate how confident you are about your answer by writing a number in the small box on the right, using the code:
4 = sure its OK 3 = probably OK 2 = 50/50 1 = probably wrong
1 PLEASE DO NOT TURN OVER UNTIL TOLD TO DO SO
ANSWER ALL QUESTIONS. PLEASE DO NOT WRITE IN THE MARGINS.
¡1 . When a dilute solution of sulphuric acid in water is electrolysed between platinum electrodes two gases are evolved.
(a) (i) State the name of the product formed at the anode ............
(ii) State the name of the product formed at the cathode ............
(b) During the early part of the electrolysis, the amount of product that collects at the anode is always somewhat less than that calculated (although this effect can be minimised by raising the temperature of the solution). Suggest a reason for the low yield at the anode.
(c) What would De the effect on the electrolysis of a limited increase in the concentration of the solution (adjustments being made to the circuit to maintain a constant current).
(d) Explain how the method of conduction of an electric current through dilute sulphuric acid differs from that through a copper wire.
2D
Question______ | SM t CM I SR I Ap I Cp | BG | CG I O IStrategy/workinq:
Any difficulties:
Question I SM I CM I SR I An | Cp | RG | C T i T o D □Strateqy/workinq:
Any difficulties:
Question______ | SM I CM I SR 1 Ap | Cp | BG I OG I O 1 | |Strateqy/workinq:
Any difficulties:
Question I SM I CM I SR I An I Cd I BG I CG X 5 D □Strategy/workinq:
Any difficulties:
Q u e s t i o n______ | SM I CM I SR I Ap 1 Cp I BG I CG I O I | |S t r a t e o v / w o r k i n q :
Any difficulties:
2. The table below gives the number of electrons present in six neutral atoms labelled E to X.
E G J L M X
Number of electrons 6 9 14 16 16 19
Use the letter at the top of a column to represent the element or one atom of the element.
(a) Which two different elements are in the same group of the periodic table?
(b) Which atoms, if any, are isotopes? ....................
(c) Which element is the best reducing agent? ...................
(d) Which element is a halogen? ...................
(e) Derive a formula for the compound formed when X reacts with M.
4D
Question SM f CM 1 SR | Ap [ Cp | BG I CG 1 O □Strategy/workinq:
Any difficulties:
Question I SM I CM I SR I A d | Cp | RG [ CG T s J □Strateqy/working:
Any difficulties:
Question______ | SM I CM | SR [ Ap I Cp I BG I OG I O 1 | |Strateqv/workinq :
Any difficulties:
Question I SM I CM I SR I A d I Cn I Bf, I CG I O I □Strateqv/workinq:
Any difficulties:
Q u e s t i o n | s m | p m | r p |' A p | r p | S t | m | n | □
S t r a t e q v / w o r k i n q :
Any difficulties:
3/5/7/9/11/13/15
3. (a) Define oxidation in terms of changes at the atomic level.
(b) Only two of the following changessubstances which are beinq oxidised.
3+ „ 2+(i) Fe --------► P0
2 *(iii) Cu --------Cu
(c) Give the names of the industrial
(i) the catalvtic oxidation of sulph
are oxidation. Underline the two
(ii) H -------- *- H+
(iv) Br2 ---------*- 2Br‘
processes which involve the following
ir (IV) oxide .
(ii) the catalytic reduction of nitrogen.
Question______ | SM f CM I SR I Ap I Cp 1 BG I CG I O ~lStrateov/workinq:
Any difficulties;
Question Î SM I CM [ SR I Ap [ Cp | RG [ CfT I E □Strateqy/workinq:
Any difficulties:
Question_______ f~SM I CM | SR 1 Ap [ Cp I BG I OG I O I | |Strateqy/workinq:
Any difficulties:
Question ! SM I CM I SR I A d I Cd | RG | CG H Ô J □Strateov/workinq:
Any difficulties:
Question______ | SM I CM I SR I Ap I Cp I BG I OG I O I 1 |Strategy/working :
Any difficulties:
V V 7 / 9 / 1 1/13/1 5
Question______ | SM f CM I SR 1 Ap I Cp | BG I CG I O 1Strategy/workinq:
Any difficulties:
Question______ | SM I CM I SR I Ap [ Cp | BG I CG I O IStrategy/workino:
Any difficulties:
Question______ | SM 1 CM | SR I Ap | Cp | BG I OG I 5~~| | |Strateqy/workinq:
□
Any difficulties:
Question | SM | CM | su | Ap | rP | un [ rr. | n | □Strategy/workinq :
Any difficulties;
Q u e s t i o n ________ 1 SM I CM I SR I Ap I Cp I BG 1 OG I O □ □S t r a t e g y / w o r K i n g :
Any difficulties :
3/5/7/9/11/13/15
5. (a) Give the formula of ammonium carbonate. .................
(b) Under suitable conditions a solid compound named urea and a colourless liquid can be obtained from ammonium carbonate. Describe how you would show by experiment that the colourless liquid is water.
(c) The formula of urea is (NHgJgCO. It is a covalent compound and is unstable on heating. Try to draw its full structural formula.
Question______ 1 SM f CM | SR | Ap I Cp 1 BG I CG I O I | 1Strateqy/workinq:
Any difficulties:
Question I SM I CM f SR | Ap | Cp | Rr. [ rr. □St rateqy/working:
Any difficulties:
Question______ f SM | CM I SR I Ap | Cp I BG I OG I O I | |St rategy/workinq:
Any difficulties:
Q u e s t i o n I SM | CM 1 SR j Ap | Cp [ iv; | c c IE □
S t r a t e o v / w o r k i n q :
Any difficulties:
Question______ | SM | CM | SR 1 Ap | Cp | BG I OG I O I [ |S t r a t e a v / w o r k i n o :
Any difficulties:
3/ V 7 / 9/11/13/15
6. Give the name of the gas evolved in each of the following reactions:
(a) manganese(IV) oxide reacts with concentrated hydrochloric acid.
Name of gas .......................................
(b) ammonium chloride is heated with calcium hydroxide.
Name of gas .......................................
(c) copper reacts with concentrated sulphuric acid.
Name of gas .......................................
Question ! SM f CM I SR I Ap | Cp [ r g | m | n [ □Strateqy/workinq:
Any difficulties:
Question I SM I CM I SR | Ap | Cp | RG [ m T Ô 3 □Strateqy/working:
Any difficulties:
Question f SM I CM I SR | Ap | Cp | RC | IT. | n □ □Strategy/workinq:
Any difficulties:
Question______ f SM 1 CM 1 SR I Ap I Cp I BG I CG I O I | |Strateov/workinq:
Any difficulties:
Question_______ I SM I CM I SR I Ap I Cp I BG I CG I O I 1 IStrateov/workino:
Any difficulties:
3/5/7/9/11/13/15
7. (a) Soap is important on account of its detergent action and is 'manufactured on a large scale. Give the chemical name of a soap.
(b) A disadvantage of soap is that its detergency is impaired in hard water Explain briefly why soap will not lather well with hard water.
(c) Describe how you would distinguish, by a chemical test, between sodium hydrogencarbonate and hydrated sodium carbonate.
Question_______ | SM [ CM I SR ! Ap I Cp | BG I CG 1 O I | |Strateqy/workinq:
Any difficulties:
Question_______ | SM I CM f SR I Ap [ Cp | BG I CG I O 1 | |Strateqy/workino:
Any difficulties:
Question I SM I CM I SR I Ap | Cp | BG [ ffi [ O □ □Strategy/workinq:
Any difficulties:
Question______ | SM | CM I SR I Ap 1 Cp 1 BG I CG T U □Strateqv/workinq:
Any difficulties;
Question I SM CM SR Ap | Cp I BG I CG | O □Strateqv/workinq :
Any difficulties:
3/5/7/9/11/13/15
APPENDIX C
Cognitive Mapping Study
APPENDIX C
COGNITIVE MAPPING STUDY
ContentsPage
Explanation of figures Cl to C3 Cl
Figure Cl: An a priori structure linking chemical concepts Cl(electrolysis) involved in solving given items
Figure C2: An a priori structure linking chemical concepts C2(periodicity and atomic structure) involved in solving given items
Figure C3: An a priori structure linking chemical concepts C2(redox) involved in solving given items
Figure C4: Cluster analysis showing the associative structureof a class of O-level students on 22 chemistry C3concepts (pre-test data)
Word association test - chemistry (cover and instructions) C4
Word association test - chemistry (example and sample page) C5
Procedures for administration of the WAT C6
Introductory notes for programs Cl to C4 C8
Program Cl: Calculation of individual relatedness matrices C9
Program C2: Printing of individual relatedness matrices CIO
Program C3: Calculation and printing of mean relatedness matrix Clland cumulative responses for all subjects
Program C4: Calculation and printing of mean related matrices Cl3and cumulative responses for selected groups of subj ects
Figure C5: Most frequent associations (%) of high and low achievers
C15
EXPLANATION OF FIGURES Cl to C3
Figures Cl to C3 represent a priori maps of problems-relevant concepts
in three overlapping topic areas. Concept labels are joined by a line
if, in the judgement of the author, either is of primary importance in
defining or describing the other in the context of O-level chemistry.
Concepts which are common to more than one map, and which therefore
represent points of overlap, have been underlined. A small number of
linking concepts, which were not judged to be problem—relevant and which
were therefore not included in the WAT, have been shown in brackets in
figures C2 and C3.
ELECTRODE
ELECTROLYSIS
ELECTRICCURRENT
ELECTROLYTEI
ATOM ELECTROCHEMICALSERIES
Figure Cl: An a priori structure linking chemical concepts(electrolysis) Involved in solving items in questions 1, 4(b) and 4(c)
PERIODIC TABLE
ISOTOPE
ATOMICMASS
\
GROUP
HALOGEN
VALENCY
FORMULA
POSITIVE NEGATIVE
ELECTRONICCONFIGURATION
CHARGE
Figure C2: An a priori structure linking chemical concepts(periodicity and atomic structure) involved in solving items in question 2
(OXIDISING REDUCINGAGENT) AGENT
(OXYGEN) ELECTRON (HYDROGEN)
Figure C3: An a priori structure linking chemical concepts(redox) involved in solving items in questions 2(c), 3, 4(a) and 4(b)
C2
PERIODICITY
V3flK303
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Q IN30V v ONionaann IN30V ° ONISIOIXOO Nonvaixo
-O Nononaax— o <mox3
NOIIVRflOIdNOOOIN03I0333339VIoiaoixad
— O 00133d
KOIV
339HI1NOIWOIV
N0I033
À0N33VA
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aaoNV
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- C3
Figure C4
Cluster analysis s
howing t
he a
ssociative s
tructure of
a class
of 0
-level s
tudents
on
22 c
hemistry c
oncepts
(N = 30:
p = 1;
"nearest n
eighbour" method^
WORD ASSOCIATION TEST
- CHEMISTRY -
DEPARTMENT OF EDUCAT ION D. Slimming
UNIVERSITY OF KEELE January 1980
UNIVERSITY OF KEELE
DEPARTMENT OF EDUCATION
WORD ASSOCIATION TEST - CHEMISTRY
I instructions:
When you see a word it often makes you think of other words. We want to find out what other words are brought to mind by seme of the words used in chemistry. On each page of this test you will find the same word written many times. Say the word to yourself and then write down the word it makes you think of next to number 1. Then say the same word to yourself again and write down the next word you think of next to number2. Continue in this way always saying to yourself the same word (which is printed on the page) and writing down the words it makes you think of, until you are told to turn to the next page.
There are no right answers, and do not worry about spelling mistakes for once they do not matter! Just write as quickly as possible.
Now please write your name here (BLOCK CAPITALS) .......................
NOW PLEASE TURN OVER AND LOOK AT THE EXAMPLE ON THE NEXT PAGE
- C4
Here: is an example:
Key word: ALKALI
1 . ALKALI acid
2 . ALKALI caustic soda
3 . ALKALI caustic potash
4. ALKALI soap
5. ALKALI pH
6 . ALKALI caustic
7 . ALKALI base
8 . ALKALI hydroxyl
9. ALKALI
10. ALKALI
PLEASE DO NOT TURN OVER UNTIL YOU ARE TOLD TO DO SO
Key word: ELECTROLYSIS
1 . ELECTROLYSIS .......................
2. ELECTROLYSIS .......................
3. ELECTROLYSIS .......................
4. ELECTROLYSIS .......................
5. ELECTROLYSIS .......................
6. ELECTROLYSIS .......................
7. ELECTROLYSIS .......................
8. ELECTROLYSIS .......................
9. ELECTROLYSIS .......................
10. ELECTROLYSIS .......................
11. ELECTROLYSIS .......................
12. ELECTROLYSIS .......................
PLEASE DO NOT TURN OVER UNTIL YOU ARE TOLD TO DO SO
- C5
PROCEDURE FOR ADMINISTRATION OF THE WAT
1. Distribute the test to all students instructing them not to open ituntil told to do so. Ensure that each has a suitable writing implement.
2. When all students have a copy of the test instruct them to open itand read the instructions. When the first students have done this say:
"When you have read the instructions please write your name clearly in block letters in the space provided. Once you have done that you may turn over and look at the example on the next page but do not turn over any more pages. When everyone is ready we will discuss the instructions before you start."
3. When all students are ready continue thus:
"First I should emphasise that there are no right answers and therefore no marks for this test. It is not a competition.However you will have only 30 seconds on each word so you should try to work as quickly as you can."
3.1 "On each page you will read a key word. This is written at the top and repeated a number of times down the left hand side as in the example in front of you, where the key word is alkali. Keep saying the word to yourself and each time write down the word it brings to mind. The reason for repeating the key word every time is to avoid what is called "chaining". "Chaining" means that the word that comes to mind is not associated with the key word, but with the last word you wrote down. For example alkali may bring to mind acid, then acid may bring to mind sulphuric, then sulphuric may bring to mind the contact process and the contact process may bring to mind catalyst and so on and so on. Obviously the contact process and catalysts are not brought directly to mind by the key word alkali, only through a sort of chain of associations. It is very easy to start chaining on this sort of test so be on the lookout and try to avoid it. Repeating the key word to yourself every time should help in this. Is everyone clear about what I mean?" (Answer any questions briefly at this stage.)
3.2 "Now here are three more things you should avoid. Number one - for any particular key word try not to repeat yourself. For example if you were writing your next response under alkali, that is number 9 in the example, you would avoid writing acid because you have already used that word. However if another key word, later inthe test, made you think of acid that would be fine. Now for the second of the don’t — don't write explanations. For example for alkali don't write that it turns litmus paper blue. We are NOT asking what you know about the key words and you should try to stick to single responses. These will usually be one word except in the case of ideas like sulphuric acid or contact process or Avogadro's number. Obviously each of these needs two words!However if an explanatory phrase does come to mind when you say the key word to yourself, you should write the important words as separate responses. So if the word alkali makes turns litmus blue pop into your mind, you should write litmus as your first response and blue as your second. And now the last of the don'ts - don't try to think too hard about what you are doing or work to any system. For example with alkali you might try to start off
- C6 -
PROCEDURE FOR ADMINISTRATION OF THE WAT
1. Distribute the test to all students instructing them not to open ituntil told to do so. Ensure that each has a suitable writing implement.
2. When all students have a copy of the test instruct them to open itand read the instructions. When the first students have done this say:
"When you have read the instructions please write your name clearly in block letters in the space provided. Once you have done that you may turn over and look at the example on the next page but do not turn over any more pages. When everyone is ready we will discuss the instructions before you start."
3. When all students are ready continue thus:
"First I should emphasise that there are no right answers and therefore no marks for this test. It is not a competition.However you will have only 30 seconds on each word so you should try to work as quickly as you can."
3.1 "On each page you will read a key word. This is written at the top and repeated a number of times down the left hand side as in the example in front of you, where the key word is alkali. Keep saying the word to yourself and each time write down the word it brings to mind. The reason for repeating the key word every time is to avoid what is called "chaining". "Chaining" means that the word that comes to mind is not associated with the key word, but with the last word you wrote down. For example alkali may bring to mind acid, then acid may bring to mind sulphuric, then sulphuric may bring to mind the contact process and the contact process may bring to mind catalyst and so on and so on. Obviously the contact process and catalysts are not brought directly to mind by the key word alkali, only through a sort of chain of associations. It is very easy to start chaining on this sort of test so be on the lookout and try to avoid it. Repeating the key word to yourself every time should help in this. Is everyone clear about what I mean?" (Answer any questions briefly at this stage.)
3.2 "Now here are three more things you should avoid. Number one - for any particular key word try not to repeat yourself. For example if you were writing your next response under alkali, that is number 9 in the example, you would avoid writing acid because you have already used that word. However if another key word, later inthe test, made you think of acid that would be fine. Now for the second of the don't - don't write explanations. For example for alkali don't write that it turns litmus paper blue. We are NOT asking what you know about the key words and you should try to stick to single responses. These will usually be one word except in the case of ideas like sulphuric acid or contact process or Avogadro's number. Obviously each of these needs two words!However if an explanatory phrase does come to mind when you say the key word to yourself, you should write the important words as separate responses. So if the word alkali makes turns litmus blue pop into your mind, you should write litmus as your first response and blue as your second. And now the last of the don'ts - don't try to think too hard about what you are doing or work to any system. For example with alkali you might try to start off
- C6
with a definition, then list all the examples you can think of and so on. Please avoid plans like this. All we want to know is what pops into your mind when you say the key word to yourself."
3.3 "So to summarise - try not to repeat yourself in any particular list, avoid deliberate plans and avoid chaining; and if an explanatory phrase happens to be the thing that is brought to mind break it up into the important words as separate responses."
4. "You will be allowed exactly 30 seconds for each key word - but there is no limit to the number of responses you may make in that time. There will be spaces for 12 words (not 10 as in the example here) and that should be more than enough for most people on most words, but if you have time for more than 12 just continue using the blank space on the right here. (Show them.) Now are there any questions?"
5. Deal with any questions, then start the test saying:
"We are going to start now. I will tell you when to turn over each page. No turning back is allowed. Please turn over and start now. ”
6. A stop watch should be used and students told to turn over every 30 seconds. If the watch is reset every time this will allow a few seconds "turning over time" - if not then allow 5 seconds between each "turn over" instruction and starting to time the next page.
- C7
INTRODUCTORY NOTES FOR PROGRAMS Cl TO C4
Although it would have been easy to combine the four FORTRAN programs given below, it proved more convenient to use them separately. They are therefore presented in that way.
Program Cl reads encoded WAT data (see Chapter 7, Section 7.1.1) from cards, calculates individual relatedness matrices and stores both the raw data and the matrix for each student on magnetic tape. The first card in the deck carries the chosen value of the parameter "p" (Garskoff and Houston, 1963; see also Chapter 5, Section 5.2.6) and the number of students ”N" using the format (II, 14). The remaining cards each represent a particular student's responses to a particular stimulus word. Each starts with a three digit student reference number (consecutive numbers from 001 to N were used and were not read by the program) and a two digit number indicating the number of words in the encoded response list which follows; this latter consists of three digit codes representing first the stimulus word and then the student's responses to it in order. The format employed is (3X, 13, 1514).The cards for the first student are arranged in order according to the sequence in which the stimulus words appear in the WAT. These cards are followed by those of the second student and so on. The taped output of this program is used as the input to programs C2, C3 and C4.
Program C2 prints individual relatedness matrices, together with the mean relatedness coefficient and the mean length of the response lists for each student.
Programme C3 calculates and prints the mean matrix for all the students, together with a cumulative list of all their responses (including the frequency of each) to each stimulus word. The mean matrix is also output to magnetic tape as input to the CLUSTAN IB suite of cluster analysis programs (Wishart, 1979).
Program C4 is a modified version of C3 which produces mean matrices and corresponding cumulative response lists for selected groups of students. Output is again to line printer and, for the matrices only, magnetic tape for subsequent cluster analysis.
1. 15 was the maximum length of any response list.
PROGRAM Cl: Calculation of individual relatedness matricesThis program reads the encoded WAT data of N subjects from cards and calculates the relatedness matrix, the mean relatedness coefficient and the mean number of responses per stimulus word for each subject. This information, together with the raw data, is output onto tape for use with programs C2, C3 or C4.
PROGRAM RCMAT(INPUT,OUTPUT,TAPE5,TAPE6=0UTPUT,TAPE4)DIMENSION RC(27,27),L(27),IWORD(27,15) [dimensions relate to number of stimulus words (27) and maximum number of responses to any stimulus word (15)]INTEGER P,RMAXDATA RMAX/27/ [number of stimulus words]READ(5,100)P,N [see introductory note for data and format for first card]
100 F0RMAT(I1,14)DO 8 M=1,N IM=0T0TRC=0.0 WRITE(4)M DO 1 1=1,RMAXREAD(5,200) LI, (IWORD(I,J1),Jl=l,LI) [see introductory note for data and format for remaining cards]
200 FORMAT(3X,13,1514)WRITE(4)LI,(IWORD(I,J1),Jl=l,LI)L(I)=LI IM=IM+LI
1 CONTINUEDO 6 1=2,RMAX IMIN1=I-1 DO 5 J=1,IMIN1 IX=L(I)IF(L(J).GT.L(I))IX=L(J)DEN=0.0 IXMIN2=IX-2 DO 2 K=1,IXMIN2
2 DEN=DEN+FLOAT((K*K)**P)DEN=DEN+FL0AT(2*(IX**P)*((IX-1)**P))RNUM=0.0LI=L(I)LJ=L(J)DO 4 Jl-l.LI DO 3 J2=l,LJIF(IWORD(I,J1).EQ.IWORD(J,J2 ) )RNUM=RNUM+FLOAT( ( (IX-J1 +1 ) * *P )
1*((IX-J2+1)**P))3 CONTINUE4 CONTINUERC(I,J)=RNUM/DEN TOTRC=TOTRC+RC(I,J )
5 CONTINUE6 CONTINUERCMEAN=2*TOTRC/FLOAT(RMAX*(RMAX-1))RM=-1.0+FLOAT(IM)/FLOAT(RMAX)DO 7 1=1,RMAXWRITE(4)(RC(I,J),J=1,RMAX)
7 CONTINUEWRITE(4)RM,RCMEAN
8 CONTINUE STOP END
- C9 -
PROGRAM C2: Printing of individual relatedness matricesThis program reads the output of program Cl and prints the relatedness matrix, the mean relatedness coefficient and the mean number of responses per stimulus word for each subject.
PROGRAM PMAT(INPUT,OUTPUT,TAPE5=INPUT,TAPE6=0UTPUT, TAPE4) DIMENSION RC(27,27),MNAME(27),IWORD(27,15) [see notes for program Cl]INTEGER RMAXDATA RMAX/27/,N/229/ [number of stimulus words, number of subjects]DATA MNAME/4HESYS,4HHAL ,4HRDN ,4HIT0P,4H-VE ,4HF0RM,4HA0DE,4H0XDN 1,4HP.T.,4HER0N,4HEYTE,4H+VE ,4HATWT,4HEDDE,4HPT0N,4HECS ,4HGRP , 24HION ,4HATN0,4HCHGE,4HEMNT,4HEC0N,4HREDA,4HVNCY,4HC0DE,4HCRNT, 34HATOM/ [4 character codes for each stimulus word]DO 14 NI=1,N READ(4)M DO 10 1=1,RMAXREAD(4)LI,(IW0RD(I,J1),J1=1,LI)
10 CONTINUEDO 11 1=1,RMAXREAD(4)(RC(I,J),J=1,RMAX)
11 CONTINUE READ(4)RM,RCMEAN WRITE(6,100)M
1001 FORMAT(20H1RC MATRIX; PUPIL NO ,13)IK=1IL=15DO 13 IB=1,2WRITE(6,1002(MNAME(IN),IN=IK,IL)
1002 FORMAT(///8X,15(3X,A4)/)IKPLU1=IK+1DO 12 I=IKPLU1,RMAX IP=MIN0(IL,1-1)WRITE(6,1003)MNAME(I),(RC(I,J),J=IK,IP)
1003 F0RMAT(4X,A4,15F7.4)12 CONTINUE
IK=16 IL=RMAX-1
13 CONTINUEWRITE(6,1004)RM,RCMEAN
1004 FORMAT(///4X,4HM = ,F7.4,4X,4HR = ,F6.4)14 CONTINUE
STOP
PROGRAM C3: Calculation and printing of mean relatedness matrix and cumulative responses for all subjects
This program reads the output of program Cl and calculates and prints the mean relatedness matrix for all subjects together the the cumulative list of responses to each stimulus word. The mean matrix is also output to tape for cluster analysis using the CLUSTAN B suite of programs.
PROGRAM MRCM(INPUT,OUTPUT,TAPE5=INPUT,TAPE 6=0UTPUT,TAPE4,TAPE11) DIMENSION MMAT(27,27),SMAT(27,27),MNAME(27) [dimensions relate to number of stimulus words]DIMENSION NWORD(2 7,200), NF(2 7,2 00),ICOUNT(2 7), IWORD(27,15) [dimensions relate to number of stimulus words (27) upper limit for cumulative number of different responses to each stimulus word (200) and the maximum length of individual response lists] INTEGER RMAX REAL MMATDATA JMAX/200/ [see notes on dimensions]DATA RMAX/27/,N/229/ [see notes for program C2]DATA MNAME/4HESYS,4HHAL ,4HRDN ,4HIPT0,4H-VE ,4HF0RM,4HA0DE,4H0XDN 1,4HP.T. ,4HER0N,4HEYTE,4H+VE ,4HATWT,4HE0DE,4HPT0N,4HECS ,4HGRP , 24HION , 4HATN0,4HCHGE, 4HEMNT, 4HEC0N, 4HREDA, 4HVNCY, 4HC0DE, 4HCRNT, 34HATOM/ [see notes for program C2]DO 21 1=1 , RMAX ICOUNT(I)=0 DO 20 J=1,JMAX NW0RD(I,J)=0 NF(I,J)=0
20 CONTINUE21 CONTINUE
DO 23 1=2,RMAX IMIN1=I-1 DO 22 J=1,IMIN1 MMAT(I,J)=0.0 SMAT(I,J)=0.0
22 CONTINUE23 CONTINUE
DO 31 NI=1, N READ(4)M DO 27 1=1,RMAXREAD(4)LI,(IWORD(I,J1),Jl=l,LI)DO 26 Jl=l,LI DO 24 J=1,JMAX IF(NWORD(I,J).EQ.0) GO TO 25 IF(IWORD(I,J1).NE.NWORD(I,J))G0 TO 24 NF(I,J)=NF(I,J)+l GO TO 26
24 CONTINUE25 NWORD(I,J)=IW0RD(I,J1)
NF(I,J)=1ICOUNT(I)=IC0UNT(I)+l
26 CONTINUE27 CONTINUE
DO 28 1=1,RMAX READ(4)(RC(I ,J),J=1,RMAX)
28 CONTINUE
- Cll
DO 30 1=2,RMAXIMIN1=I-1DO 29 J=1,IMIN1SMAT(I,J)=SMAT(I,J)+RC(I, J)
29 CONTINUE30 CONTINUE
READ( 4 ) RM,RCMEAN31 CONTINUE
D033 1=2,RMAX IMIN1=I-1DO 32 J=1,IMIN1MMAT(I,J)=SMAT(I,J )/FLOAT(N)
32 CONTINUE33 CONTINUE
WRITE(6,1001)1001 FORMAT(l9H1 MEAN RC MATRIX)
IK=1IL=I5DO 35 IB=1,2WRITE(6,1002)(MNAME(IN),IN=IK,IL)
1002 FORMAT////8X,15(3X,A4)/)IKPLU1=IK+1DO 34 I=IKPLU1,RMAX IP=MIN0(IL,1-1)WRITE(6,1003)MNAME(I),(MMAT(I,J),J=IK, IP)
1003 FORMAT/4X,A4,15F7.4)34 CONTINUE
IK=16 IL=RMAX-1
35 CONTINUEDO 36 I-1,RMAXWRITE(6,1004)I,MNAME(I)
1004 FORMAT/////18H STIMULUS WORD ,I2,3H (,A4,1H)) ICOI=ICOUNT(I)WRITE(6,1005)(NWORD(I,J ),NF(I,J ),J=1,ICOI)
1005 FORMAT(10/4X,13,1H/,13)/)36 CONTINUE
DO 37 1=2,RMAX IMIN1=I-1WRITE(11,1006)(MMAT(I,J),J=1,IMIN1)
1006 FORMAT/22F6.4/5F6.4) [format to write 27 x 27 matrix to tape for CLUSTAN B]
37 CONTINUE STOP END
- C12
PROGRAM C4: Calculation and printing of mean relatedness matrices and cumulative responses for selected groups of subjects
This program reads the output of program Cl and calculates and prints mean relatedness matrices together with corresponding cumulative lists of responses to each stimulus word for selected groups of subjects. It differs from program C3 only with respect to the lines highlined in colour.
PROGRAM MRCM(INPUT,OUTPUT,TAPE5=INPUT,TAPE6=0UTPUT,TAPE4,TAPE11) DIMENSION MMAT(27,27),SMAT(27,27),RC(27,27),MNAME(27) [see notes for program C3]DIMENSION NWORD(27,200),NF(27,200),ICOUNT(27),IWORD(27,15) [see notes for program C3]DIMENSION MSEL(29,2) [dimension relates to number of subjects in largest group (29) and number of groups (2)]INTEGER RMAX, SMAX REAL MMATDATA JMAX/200/ [see notes for program C3]DATA RMAX/27/,N/229/ [see notes for program C2]DATA SMAX/2/ [number of groups (2)]DATA MNAME/4HESYS,4HHAL ,4HRDN .4HIT0P,4H-VE ,4HF0RM,4HA0DE,4H0XDN 1,4HP.T.,4HER0N,4HEYTE,4H+VE ,4HATWT,4HE0DE,4HPT0N,4HECS ,4HGRP , 24HION ,4HATN0,4HCHGE,4HEMNT,4HEC0N,4HREDA,4HVNCY,4HC0DE,4HCRNT, 34HATOM/ [see notes for program C2]DATA MSEL/11,20,35,47,56,75,78,89,90,95,103,104,127,134,138,139, 1141,145,146,158,161,162,166,206,216,217,218,219,225,26,7,21,60,61,62,63,65,66,97,98,106,119,170,171,175,178,180,183, 3190,191,193,194,227,228,229,0,0,0/ [code numbers of selected subjects, group by group; 'missing' subjects in small group represented by zeros (0)]DO 38 IT=1,SMAX DO 21 1=1,RMAX ICOUNT(I)=0 DO 20 J=1,JMAX NWORD(I,J)=0
20 CONTINUE21 CONTINUE
DO 23 1=2,RMAX IMIN1=I-1 DO 22 J=1,IMIN1 MMAT(I,J)=0.0 SMAT(I,J)=0.0
22 CONTINUE23 CONTINUE
ISEL=131 DO 31 NI-l.N
READ(4)M DO 27 1=1,RMAXREAD(4)LI,(IW0RD(I,J1),Jl=l,LI)IF(M.NE.MSEL(ISEL,IT)G0 TO 27 DO 26 Jl=l ,LI DO 24 J=1,JMAX IF(NWORD(I,J).EQ.0) GO TO 25 IF(IW0RD(I,J1).NE.NW0RD(I,J))G0 TO 24 NF(I,J)=NF(I,J)+l
24 CONTINUE25 NWORD(I,J)=IWORD(I,Jl)
NF(I,J)=1ICOUNT(I)=ICOUNT(I)+l
26 CONTINUE27 CONTINUE
DO 28 1=1,RMAX READ(4)(RC(I,J),J=1,RMAX)
28 CONTINUE READ(4)RM,RCMEANIF(M.NE.MSEL(ISEL,IT))GO TO 31ISEL=ISEL+1DO 30 1=2,RMAXIMIN1=I-1DO 29 J=1,IMIN1SMAT(I,J)=SMAT(I,J)+RC(I,J)
29 CONTINUE30 CONTINUE
[line omitted from program C3]31 CONTINUE
DO 33 1=2, RMAXIMIN1-I-1DO 32 J=1,IMIN1MMAT(I,J)=SMAT(I,J)/FLOAT(ISEL)
32 CONTINUE33 CONTINUE
WRITE (6,1000)IT1000 F0RMAT(26H1 MEAN RC MATRIX; GROUP,12)
IK=1IL-15DO 35 IB=1,2WRITE(6,1002)(MNAME(IN),IN=IK, IL)
1002 FORMAT(///8X,15(3X,A4)/)IKPLU1=IK+1DO 34 I=IKPLU1,RMAX IP=MIN0(IL,1-1)WRITE(6,1003)MNAME(I),(MMAT(I,J),J=IK, IP)
1003 FORMAT(4X,A4,15F7.4)34 CONTINUE
IK=16 IL=RMAX-1
35 CONTINUEDO 36 1=1,RMAXWRITE(6,1004)I,MNAME(I)
1004 FORMAT(////18H STIMULUS WORD ,12,3H (,A4,1H)) ICOI=ICOUNT(I)WRITE(6,1005)(NWORD(I,J), NF(I,J), J=1,ICOI)
1005 FORMAT(10(4X,I3,1H/,I3)/)36 CONTINUE
DO 37 1=2,RMAX IMINL=I-1WRITE(11,1006)(MMAT(I,J),J=1,IMIN1)
1006 FORMAT(22F6.4/5F6.4) [see notes for program C3]37 CONTINUE
REWIND 438 CONTINUE
STOP END
- C14 -
Response frequency 0% 20% 40% 60% 80% 100% 1 1 1 1 i 1
STIMULUS high achieversresponse » low achievers
* p < 0.05 ** p < 0.01
ELECTROLYSIScathode y_______— .....................................-1— -1
anode 'h -'- ----------------------------- ~~ i
ion* t ' _ j
electricity 1------------------ ---- T *
electrode 1------------ T------’
electrolyte L j - J
positive** F --------------
ELECTRODE[■ -------- ----- , 3cathode
anode !■ .............. • ............... ■“ __— f ~ ••
electrolysis h — ------------ —=-------r— 1
electricity 1------ ' —
positive l ----- — J
negative F - — ■ ------ i
ELECTRIC CURRENTelectrons i— — ------r — i —amps Í— - --------- !electrolysis L _ ' ' — dvolts b — ,_:_i 1flow 1— ~ — .
ANODEcathode y ------------ -• '-3electrolysispositiveelectrode**
1 :----— ---------------- i
F— - , 'ion
CATHODEanode 3negative r - ... ' "i ielectrolysis ^ _ - — 1 • - !electrode
p - - , .
electron F --'r-
;ure C5 Most freq achievers
- CIA -
Response frequency 0% 20% 40% 60% I ' l l
ELECTROLYTEelectrolysis F — d-z--- - ' ~solution*electricity E = f ± = = i = = .
IONpositive ,--------■'negative E = -------- ------- —electron F - - — -atom — ■ ",,i 1electrolysis — — icharge**
ELECTROCHEMICAL SERIESreactivitymetalsodium**
OXIDATION oxygen reduction* electron** hydrogen loss etc gain etc
REDUCTION oxidation** hydrogen* oxygen electron* redox* loss etc
REDUCING AGENT reduction hydrogenoxidising agent*oxygenelectron*
CHARGEpositivenegativeion**electronelectric(ity)Figure C5 Most frequent associations (%) of high and loy
achievers (cont.)
100%
- CIS
Response frequency
POSITIVEnegativeprotonanodeioncharge
2<p% 40% 60% 80%I T i
NEGATIVEpositiveion**cathodeelectroncharge
ATOMelementelectronionneutron*nucleus*proton*molecule
3
PROTONpositive**neutronelectronatomnucleus* atomic number
ELECTRON negative* atom proton orbit/shell neutron
ELECTRONICCONFIGURATION
electron* orbit/shell energy-level ion
3
2223
Figure C5 Most frequent associations (%) of high and low achievers (cont.)
- C16 -
100%!
j
Response frequency 0% 20 % 40% 60% 80% 100%
VALENCYelectron** |- ^ C ^ ^ '----'-— -'-—- Ibond(ing)** ,number hi.. . :---------- - ■combining power**periodic table n
FORMULA
equation 1 - --- ^ ' - f * ' ■ '!compound**symbol* L E f ------ ^moleculevalency Ë ± ± T — Jreaction* r ' ■ ■
ATOMIC MASSprotonelectronneutron ¡ ' " ' . . H I — . ^
numberatomic number
ATOMIC NUMBERproton F - - - - - - F i
periodic tableatomic mass Y " " " - : ' ................jneutron If ..... ■,electron
ISOTOPEneutron r ' r .: i------atom IfF.f . -j - ^radio-active*chlorine
ELEMENTcompound* E. Fv::r------atom —— ' — r ■ -metal Eb : 1periodic table 1----------- ----- 1
Figure C5 Most frequent associations (%) of high and lowachievers (cont.)
C17
Response frequency 0%I 20%I 40%! 60%I
PERIODIC TABLEgroupelement
1— . .......... - 77..1
period .. ..i 1atomic number U--r— ----1--------1hydrogenmetal* ...........■
GROUPperiodic tablehalogen t _ ■ ! ----periodnumber t = ± = ± = = lelement* F-' --n - 7metal* -------- ,
HALOGEN
chlorine* ---- -7- - -----"f -7 -7 ----- -«-VIiodine* K - •• - r--- ^bromine ^ j
fluorine K ------ 'I 17
Figure C5 Most frequent associations (%) of high and low achievers (concluded)
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