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ST ANDREWS JUNIOR COLLEGE
JC 1 FINAL EXAMINATION H2 CHEMISTRY
03 October 2011 2 hr 30 min
Additional materials: Data Booklet
INSTRUCTIONS TO CANDIDATES
Sections A and B (20 marks)
There are 20 questions in these sections. Answer all
questions.
For each question there are four possible answers A, B, C and D.
Choose the one you consider correct
and record your choice in soft pencil on the Optical Answer
Sheet.
For Sections C and D
Write in dark blue or black pen.
You may use a soft pencil for any diagrams, graphs or rough
working.
Do not use staples, paper clips, highlighters, glue or
correction fluid.
You are reminded of the need for good English and clear
presentation in your answers.
The number of marks is given in brackets [ ] at the end of each
question or part question.
Section C (40 marks)
Answer ALL the questions.
Section D (20 marks)
Answer ALL the questions in the space provided on the question
paper.
----------------- This set of question paper consists of 10
printed pages including this page ---------------------
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SECTION A
For each question there are four possible answers, A, B, C and
D. Choose the one you consider to be
correct.
1. Which of the following has the largest amount of
particles?
A 6.02 x 1022 atoms of neon
B copper ions in 500 cm3 of 0.1 mol dm-3 of copper(I) sulfate
solution
C ions in 3.30 g of solid iron(III) oxide
D molecules in 2.3 x 10-3 m3 of ethane at standard temperature
and pressure conditions
2. 25.0 cm3 of 0.025 mol dm-3 acidified potassium manganate(VII)
completely reacted with 20.0
cm3 of 0.0625 mol dm-3 hydrogen peroxide solution. What is the
final oxidation state of
manganese at the end of this reaction?
A +2 B +3 C +4 D +7
3. Which of the following ions has the most number of unpaired
electrons?
A N B C C Ti2+ D Cu2+
4. Which of the following data accurately describes the number
of each type of hybrid carbons
present in all the carbon-containing products of the reaction of
2-ethylpenta-1,3-diene with hot
acidified potassium manganate(VII) solution?
sp sp2 sp3
A 0 3 4
B 0 4 3
C 1 2 4
D 1 3 3
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5. Upon mixing water and ethanol, with the following structure,
and leaving it to stand would result
in the formation of a homogeneous solution. Which of the
following accurately describes their
intermolecular interactions?
Interactions present between
ethanal-ethanal water-water ethanal-water
A hydrogen bonding hydrogen bonding hydrogen bonding
B
permanent dipole-
permanent dipole hydrogen bonding hydrogen bonding
C
permanent dipole-
permanent dipole hydrogen bonding
permanent dipole-
permanent dipole
D
permanent dipole-
permanent dipole
permanent dipole-
permanent dipole
permanent dipole-
permanent dipole
6. A container with a volume of 2 dm3 contains 15 kPa of neon
was connected to another container
with a volume of 4 dm3 containing 25 kPa of argon. If the
containers are connected at constant
temperature, what is the final pressure exerted by the noble
gases?
A 18.3 kPa B 20.0 kPa C 21.7 kPa D 40.0 kPa
7. Using the following data, what is the standard enthalpy
change for the reaction between ethane
and chlorine to form liquid 1,2-dichloroethane and white fumes
of hydrogen chloride?
Enthalpy change of formation of
ethane(g) -83.9 kJ mol-1
1,2-dichloroethane(l) -169.8 kJ mol-1
hydrogen chloride(g) -91.0 kJ mol-1
A -267.9 kJ mol-1 B -176.9 kJ mol-1 C +176.9 kJ mol-1 D +267.9
kJ mol-1
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8. Which of the following statements is an accurate description
of the energy terms?
Equation Enthalpy change of H S
A H2(g) H(g) atomisation positive positive
B Na+(g) + Cl(g) NaCl(s) formation negative negative
C O2-(g) O-(g) + e ionisation energy positive positive
D Ba(OH)2(aq) + H2SO4(aq)
BaSO4(s) + 2H2O(l) neutralisation negative positive
9. Which of the following statements is incorrect?
A During free radical substitution, the bond angle (centred
around the carbon radical)
changes.
B During electrophilic addition, a carbocation is formed in the
fast step.
C During electrophilic substitution, the carbocation
intermediate has 4 electrons delocalised
over 5 carbon atoms in the benzene ring.
D During nucleophilic substitution (SN2), the transition state
is made up of a pentavalent
carbon which could be negatively charged.
10. Which of the following statements about but-2-ene is
incorrect?
A The trans-isomer has a higher melting point than the
cis-isomer.
B It can be obtained from the dehydration of butan-2-ol.
C It decolourises purple acidified potassium manganate(VII) to
form only one organic
product.
D It decolourises orange-red bromine water to form
2,3-dibromobutane as the major product.
11. Reaction of propene with chlorine in the presence of aqueous
sodium nitrate gives a mixture of
products.
Which set of products will be present in this mixture?
A CH2(OH)CH2CH2Cl CH3CHClCH2Cl CH3CH(ONO2)CH2Cl
B CH3CH(OH)CH2ONO2 CH3CHClCH2ONO2 CH3CHClCH2Cl
C CH2ClCH2CH2Cl CH3CH(ONO2)CH2Cl CH3CH(OH)CH2Cl
D CH3CHClCH2Cl CH3CH(ONO2)CH2Cl CH3CH(OH)CH2Cl
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12. Which of the following accurately depicts the rate of
hydrolysis?
A
B
C
D
13. Which of the following pairs of organic compounds would have
the same observations upon
addition of aqueous bromine?
A 2-methylphenol and benzene C propene and but-1-ene
B but-2-ene and phenol D hex-1-ene and benzene
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14. After Compound A, with the following structure, has been
reacted with hot aqueous alkaline
iodine solution, which of the following options depicts the
correct product?
A
C
B
D
15. Which of the following accurately depicts the synthesis
process for the production of propanoic
acid from but-2-ene?
A oxidation, electrophilic addition, acidification
B electrophilic addition, acidification, oxidation
C oxidation, acidification, electrophilic addition
D electrophilic addition, oxidation, acidification
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SECTION B
For each of the questions in this section, one or more of the
three numbered statements 1 to 3 may be correct. The responses A to
D should be selected on the basis of
A B C D
1, 2 and 3 are correct
1 and 2 only are correct
2 and 3 only are correct
1 only is correct
16. Which of the following reactions illustrates
disproportionation?
1 MnO
+ Mn2+ 2MnO2
2 Cl2 + 2OH Cl + ClO + H2O
3 2Cu+ Cu + Cu2+
17. Which of the following statements with regards to ideal
gases are true?
1 All ideal gases cannot be liquefied.
2 All particles within the ideal gases are stationary at 0
K.
3 The total volume of the particles is equal to the volume of
the container.
18. Which reactions represent enthalpy changes of formation?
1
S8(s) + O2(g) SO2(g)
2 C(graphite) C(g)
3 Na(s) + H2O(l) NaOH(aq) + H2(g)
19. Which of the following products can be formed from
4-nitromethylbenzene?
1
2
3
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The responses A to D should be selected on the basis of
A B C D
1, 2 and 3 are correct
1 and 2 only are correct
2 and 3 only are correct
1 only is correct
20. Deuterium (D = 2H) and hydrogen are isotopes and possesses
similar chemical properties.
Which reactions yield a carbon compound incorporating
deuterium?
1
2
3
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SECTION C Answer ALL questions on the provided writing
paper.
1. One of the more common catalysts used in reactions with
benzene is aluminium bromide, which
appears as a white powder. Aluminium bromide is formed when
aluminium is reacted with
hydrobromic acid.
(a) i) Write out the balanced equation for the standard enthalpy
change of formation of
aluminium bromide.
.
ii) Given the following information and relevant information
from the Data Booklet,
construct an energy level diagram and calculate the strength of
each bond within
aluminium bromide.
Hatm(aluminium) +326 kJ mol-1
Hf(AlBr3(s)) -511.3 kJ mol-1
sublimation of AlBr3(s) +100.8 kJ mol-1
vaporisation of Br2(l) +30.0 kJ mol-1
iii) Describe and name the mechanism of the reaction between
liquid bromine and
methylbenzene at 30oC, using aluminium bromide as the halogen
carrier. State the
observation.
iv) Explain why the organic product formed in part (iii) could
not undergo alkaline
hydrolysis.
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(b) Suggest the reagents and conditions for each step, and draw
the structural formula of
every intermediate compound formed, for the conversion of
i) propane to ethanoic acid in 3 steps and
ii) 2-chlorobutane to 2-methylbutanoic acid in 2 steps.
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2. One of the commonly used examples of halogenoalkanes is
2-bromopentane, which is a pale
yellow liquid.
(a) Illustrate with a diagram, using displayed formulae, to show
how 2-bromopentane is able to
display optical isomerism.
[3]
(b) i) B is the organic product of the reaction between
2-bromopentane and aqueous
potassium hydroxide. Given that B is able to rotate
plane-polarised light, outline the
mechanism of the reaction.
ii) Explain the following observations made of B:
I. B is soluble in water
II. The bond angle about the chiral carbon atom is larger than
the bond angle
about oxygen atom.
[6]
(c) 3.28 g of an unknown liquid hydrocarbon, C, was vapourised
and found to take up 202 cm3
under 497436 Pa and 29 oC. It was then exploded in the presence
of excess amount of
oxygen, which resulted in a contraction of 707 cm3.
Using the information from the Data Booklet and given that water
has a boiling point >70 oC
at 497436 Pa, determine the molecular relative mass and the
molecular formula of C.
[3]
(d) Another hydrocarbon, D, has the molecular formula C6H10, and
does not possess any
stereoisomerism. It decolourises aqueous bromine and reacts with
gaseous hydrogen
bromide to form compound E. D also decolourises hot acidified
potassium manganate(VII)
to form one organic product having structural formula
CH3COCH2COOH.
Suggest the structural formula for D and E, explaining your
reasoning. Label any chiral
carbon atoms present in D and E with an asterisk (*). Write
balanced equations for all
reactions of D.
[8]
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Name: Class:
ST ANDREWS JUNIOR COLLEGE
JC1 Final Year Examinations Section D
Candidates answer in the spaces provided on the question
paper.
Additional Materials: Data Booklet
READ THESE INSTRUCTIONS FIRST
You may use a soft pencil for any diagrams, graphs or rough
working.
Do not use staples, paper clips, highlighters, glue or
correction fluid.
Answer all questions.
You are reminded of the need for good English and clear
presentation in your answers.
The number of marks is given in brackets [ ] at the end of each
question or part
question.
For Examiners Use:
Question Marks
1
2
Total (20 marks)
--------- This set of question paper consists of 10 printed
pages including this page -------------
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1. (a) Chromium is one of the transition metals commonly used in
organic chemistry as it is able
to exhibit variable oxidation states and its oxo-anions (CrO42-
and Cr2O7
2-) are used
commonly as oxidising agents.
i) Write the electronic configuration of chromium in the
following substances:
I. Cr(s) ___________________________________________________
II. Cr(OH)3(s)
___________________________________________________
III. K2Cr2O7(aq)
___________________________________________________
[3]
(b) Given that orange acidified potassium dichromate(VI)
solution is able to oxidise primary
alcohols to their respective carboxylic acids while itself is
reduced to form green
chromium(III) ion.
i) Given the following half equation for the reduction of
dichromate(VI), write the half
equation for the oxidation of butan-1-ol to butanoic acid, and
hence write the
balanced redox equation for the reaction of acidified potassium
dichromate(VI) with
butan-1-ol.
Cr2O72- + 14H+ + 6e- 2Cr3+ + 7H2O
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1. (b) ii) A chemist extracted 5.00 g from an organic sample
labelled as F and dissolved it in
deionised water and diluted it to 250 cm3 through a standard
flask, and labelled it as
FA1.
An aliquot of 10.0 cm3 of FA1 was extracted and titrated against
a standard solution
of 0.05 mol dm-3 acidified potassium dichromate(VI). The
experiment was repeated
and an average titre volume of 25.35 cm3 was obtained. Using
your derived
equation in (b)(i) and assuming that butan-1-ol is the only
substance that could be
oxidised in F, determine the percentage composition by mass of
butan-1-ol in F.
[5]
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2. (a) For the following synthesis, suggest the structural
formula of compounds G, H and J. For
reactions I and II, suggest reagents and/or conditions. Fill in
your answers in the table
below.
Compound G Compound H Compound J
Reagents and Conditions
Reaction I
Reaction II
[5]
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2. (b) For each of the following pairs of compounds,
i) suggest a chemical test, stating clearly the reagents and
conditions, that could be
used to distinguish the compound on the left from the compound
on the right.
ii) state clearly the observations that could be taken, and
iii) write out the balanced equation for the positive tests.
I. C6H5Br and CH3CH2CH2Cl, and
i) Reagents and conditions
ii) Observations
iii) Balanced Equation(s)
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2. (b) For each of the following pairs of compounds,
i) suggest a chemical test, stating clearly the reagents and
conditions, that could be
used to distinguish the compound on the left from the compound
on the right.
ii) state clearly the observations that could be taken, and
iii) write out the balanced equation for the positive tests.
II. hex-1-ene and hexane
i) Reagents and conditions
ii) Observations
iii) Balanced Equation(s)
[7]
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