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*OCE/16026*
GENERAL CERTIFICATE OF SECONDARY EDUCATION
TWENTY FIRST CENTURY SCIENCE A323/01CHEMISTRY AUnit 3: Ideas in Context plus C7 (Foundation Tier)
F
INSTRUCTIONS TO CANDIDATES
• Write your name clearly in capital letters, your Centre Number and Candidate Number in the boxes above.• Use black ink. Pencil may be used for graphs and diagrams only.• Read each question carefully and make sure that you know what you have to do before starting your answer.• Answer all the questions.• Do not write in the bar codes.• Write your answer to each question in the space provided. Additional paper may be used if necessary but
you must clearly show your Candidate Number, Centre Number and question number(s).
INFORMATION FOR CANDIDATES
• The number of marks is given in brackets [ ] at the end of each question or part question.• The total number of marks for this paper is 55.• Where you see this icon you will be awarded a mark for the quality of written communication in
your answer.
• The Periodic Table is printed on the back page.• This document consists of 12 pages. Any blank pages are indicated.
4 A scientist employed by the Food Standards Agency uses paper chromatography. He tests samples of water-soluble food dyes to see if they contain a banned compound.
The resulting chromatogram is shown below.
A B C D bannedcompound
dyes
start line
solvent front
(a) Describe how the scientist carries out this chromatography.
OCR is committed to seeking permission to reproduce all third-party content that it uses in its assessment materials. OCR has attempted to identify and contact all copyright holders whose work is used in this paper. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced in the OCR Copyright Acknowledgements Booklet. This is produced for each series of examinations, is given to all schools that receive assessment material and is freely available to download from our public website (www.ocr.org.uk) after the live examination series.
If OCR has unwittingly failed to correctly acknowledge or clear any third-party content in this assessment material, OCR will be happy to correct its mistake at the earliest possible opportunity.
For queries or further information please contact the Copyright Team, First Floor, 9 Hills Road, Cambridge CB2 1GE.
OCR is part of the Cambridge Assessment Group; Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
Additional Guidance within any mark scheme takes precedence over the following guidance. 1. Mark strictly to the mark scheme.
2. Make no deductions for wrong work after an acceptable answer unless the mark scheme says otherwise.
3. Accept any clear, unambiguous response which is correct, e.g. mis-spellings if phonetically correct (but check additional guidance).
4. Abbreviations, annotations and conventions used in the detailed mark scheme:
/ = alternative and acceptable answers for the same marking point (1) = separates marking points not/reject = answers which are not worthy of credit ignore = statements which are irrelevant - applies to neutral answers allow/accept = answers that can be accepted (words) = words which are not essential to gain credit words = underlined words must be present in answer to score a mark ecf = error carried forward AW/owtte = alternative wording ORA = or reverse argument E.g. mark scheme shows ‘work done in lifting / (change in) gravitational potential energy’ (1) work done = 0 marks work done lifting = 1 mark change in potential energy = 0 marks gravitational potential energy = 1 mark
5. Annotations: The following annotations are available on SCORIS.
= correct response = incorrect response bod = benefit of the doubt nbod = benefit of the doubt not given ECF = error carried forward ^ = information omitted I = ignore R = reject
6. If a candidate alters his/her response, examiners should accept the alteration.
7. Crossed out answers should be considered only if no other response has been made. When marking crossed out responses, accept correct answers which are clear and unambiguous.
1
A323/01 Mark Scheme June 2010
2
E.g. For a one mark question, where ticks in boxes 3 and 4 are required for the mark:
Put ticks () in the two correct boxes.
This would be worth 0 marks.
Put ticks () in the two correct boxes.
This would be worth one mark.
Put ticks () in the two correct boxes.
This would be worth one mark.
8. The list principle: If a list of responses greater than the number requested is given, work through the list from the beginning. Award one mark for each correct response, ignore any neutral response, and deduct one mark for any incorrect response, e.g. one which has an error of science. If the number of incorrect responses is equal to or greater than the number of correct responses, no marks are awarded. A neutral response is correct but irrelevant to the question.
9. Marking method for tick boxes:
Always check the additional guidance.
If there is a set of boxes, some of which should be ticked and others left empty, then judge the entire set of boxes. If there is at least one tick, ignore crosses. If there are no ticks, accept clear, unambiguous indications, e.g. shading or crosses. Credit should be given for each box correctly ticked. If more boxes are ticked than there are correct answers, then deduct one mark for each additional tick. Candidates cannot score less than zero marks.
E.g. If a question requires candidates to identify a city in England, then in the boxes
Edinburgh Manchester Paris Southampton
the second and fourth boxes should have ticks (or other clear indication of choice) and the first and third should be blank (or have indication of choice crossed out).
Edinburgh Manchester × Paris Southampton × Score: 2 2 1 1 1 1 0 0 0 NR
A323/01 Mark Scheme June 2010
Question Expected Answer Mark Additional Guidance 1 a i more can be grown (1) [1] allow cotton can be planted again ii any two from:
reference to using fertilisers; reference to using pesticides; cotton is bleached (using harmful chemicals);
[2]
iii these polymers are made from crude oil (1) (crude) oil/polymers are finite/will one day run out/is not renewable (1)
[2]
b they are easier to use/more convenient / they do not need to be washed / they are kinder to a baby's skin (1)
[1] allow more comfortable for baby / less likely to leak do not allow economy answers
c i from getting the raw material used to make the product to the disposal of the product (1)
[1] do not allow answers that start from making product from raw material
ii any two from: making materials; making the products from the materials; using the products; disposing of the products;
[2]
d i raw material production (1) manufacture of components (1)
[2]
ii (generation) of electricity used(1) manufacture of detergent (1)
[2]
Total [13]
3
A323/01 Mark Scheme June 2010
Question Expected Answer Mark Additional Guidance
2 a i alcohols (1) [1] ii C2H6O (1) [1] accept C2H5OH b liquid;
yes; yes no
[3] all four correct = 3 marks three correct = 2 marks two correct = 1 mark
c i sugar/glucose (1) [1] ii (high concentration of) ethanol kills yeast (1) [1] allow the ethanol denatures/destroys the yeast
allow ethanol denatures enzymes but do not allow kills enzymes
iii distillation (1) plus any two from: mixture is heated/evaporated/boiled; vapour cooled to condense it; ethanol has lower boiling point (so boils off first);
[3] allow fractional distillation allow explanation marks independent of name but do not give marks for a method that does not separate eg reflux
Total [10] 3 a i energy level of reactants is higher than that of products (1)
so energy/heat given out during the reaction (1) [2] allow energy level at end is lower than at beginning /
energy level goes down / energy change is negative ii methane + oxygen → carbon dioxide + water (1) [1] Accept symbol equation if correct b taken in/gained/endothermic
given out/released/exothermic [1] both required for the mark
c energy needed to start a reaction (1) energy needed to break bonds (1)
[2] allow first mark for energy needed for a reaction to take place/begin / energy needed for successful collisions ignore reference to catalysts
Total [6]
4
A323/01 Mark Scheme June 2010
Question Expected Answer Mark Additional Guidance
4 a any three from: put spots of dyes (on origin); put end of paper in water; in a beaker; leave; until water is nearly at the top of the paper; observe how far dyes have travelled; QWC mark is for an answer that contains at least ten words with no more than one incorrect spelling in each ten words
[3]
[1]
allow other acceptable containers
b i maximum position of solvent travel (1) [1] ii pen ink smudges/runs/dissolves in the water (1) [1] c i C (1) [1] ii one spot from C travelled same distance up paper as the
spot from the banned compound (1) [1] allow C has a spot at the same level as banned
compound iii distance travelled by solvent (1)
distance travelled by (banned) dye (1) [2]
Total [10] 5 a i measure out 25.0 cm3 of the stock solution (1)
make up to 250 cm3 with (distilled/deionised) water (1) [2] allow one mark for adding 1 part stock solution to 9
parts water ignore references to dilution to a tenth of stock concentration
ii g/dm3 (1) [1] b i not accurate (1) [1] ii pipette (1) [1] allow burette iii to give a colour change (1)
when the alkali has been neutralised / when the solution is neutral (1)
[2] allow to determine the end point = 2 marks allow fully reacted
Total [7]
5
A323/01 Mark Scheme June 2010
6
Question Expected Answer Mark Additional Guidance
6 a i a chemical that is made in large quantities (1) [1] ii (to show that) the reaction is reversible / goes backwards
and forwards (1) [1] allow to show that it is a (dynamic) equilibrium
b air makes the process (more) sustainable(1) because the supply of air is not limited / air is renewable(1) natural gas makes the process less/not sustainable(1) because it is finite/will one day run out/not renewable(1)
[4]
c speed up the reaction (1) [1] accept provides an alternative route / lowers activation energy
d any two from: tanker vessel must be strong/pressurised/have thick walls; tanker vessel must be leak proof; tanker must carry a hazard warning sign; speed limits for heavy vehicles;
[2] allow no naked flames
Total [9]
OCR (Oxford Cambridge and RSA Examinations) 1 Hills Road Cambridge CB1 2EU OCR Customer Contact Centre 14 – 19 Qualifications (General) Telephone: 01223 553998 Facsimile: 01223 552627 Email: [email protected] www.ocr.org.uk For staff training purposes and as part of our quality assurance programme your call may be recorded or monitored
TWENTY FIRST CENTURY SCIENCE A323/02CHEMISTRY AUnit 3: Ideas in Context plus C7 (Higher Tier)
H
INSTRUCTIONS TO CANDIDATES
• Write your name clearly in capital letters, your Centre Number and Candidate Number in the boxes above.• Use black ink. Pencil may be used for graphs and diagrams only.• Read each question carefully and make sure that you know what you have to do before starting your answer.• Answer all the questions.• Do not write in the bar codes.• Write your answer to each question in the space provided. Additional paper may be used if necessary but
you must clearly show your Candidate Number, Centre Number and question number(s).
INFORMATION FOR CANDIDATES
• The number of marks is given in brackets [ ] at the end of each question or part question.• The total number of marks for this paper is 55.• Where you see this icon you will be awarded a mark for the quality of written communication in
your answer.
• The Periodic Table is printed on the back page.• This document consists of 16 pages. Any blank pages are indicated.
4 A scientist employed by the Food Standards Agency uses paper chromatography. He tests samples of water-soluble food dyes to see if they contain a banned compound.
The resulting chromatogram is shown below.
A B C D bannedcompound
dyes
start line
solvent front
1 cm
2
3
4
5
6
7
(a) The chromatogram shows that dye C contains the banned compound.
The identity of this substance can be confirmed using its published Rf value.
(i) Calculate the Rf value for the banned compound.
You must show your working.
Rf value =
distance travelled by solutedistance travelled by solvent
Rf value = ......................................................... [2]
(ii) Nitric acid and sodium hydroxide react according to the following equation.
HNO3 + NaOH NaNO3 + H2O
The relative formula mass of nitric acid is 63 and the relative formula mass of sodium hydroxide is 40.
Calculate the mass of sodium hydroxide in 25.0 cm3 of the sodium hydroxide solution, and hence find the concentration of the sodium hydroxide solution in g/dm3.
You should show your working.
mass of the sodium hydroxide in 25 cm3 solution = ............................. g
concentration of sodium hydroxide solution = ............................. g/dm3 [3]
(iii) Use the titration results to assess the degree of uncertainty in your value for the concentration of the sodium hydroxide solution.
OCR is committed to seeking permission to reproduce all third-party content that it uses in its assessment materials. OCR has attempted to identify and contact all copyright holders whose work is used in this paper. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced in the OCR Copyright Acknowledgements Booklet. This is produced for each series of examinations, is given to all schools that receive assessment material and is freely available to download from our public website (www.ocr.org.uk) after the live examination series.
If OCR has unwittingly failed to correctly acknowledge or clear any third-party content in this assessment material, OCR will be happy to correct its mistake at the earliest possible opportunity.
For queries or further information please contact the Copyright Team, First Floor, 9 Hills Road, Cambridge CB2 1GE.
OCR is part of the Cambridge Assessment Group; Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
Additional Guidance within any mark scheme takes precedence over the following guidance. 1. Mark strictly to the mark scheme.
2. Make no deductions for wrong work after an acceptable answer unless the mark scheme says otherwise.
3. Accept any clear, unambiguous response which is correct, e.g. mis-spellings if phonetically correct (but check additional guidance).
4. Abbreviations, annotations and conventions used in the detailed mark scheme:
/ = alternative and acceptable answers for the same marking point (1) = separates marking points not/reject = answers which are not worthy of credit ignore = statements which are irrelevant - applies to neutral answers allow/accept = answers that can be accepted (words) = words which are not essential to gain credit words = underlined words must be present in answer to score a mark ecf = error carried forward AW/owtte = alternative wording ORA = or reverse argument E.g. mark scheme shows ‘work done in lifting / (change in) gravitational potential energy’ (1) work done = 0 marks work done lifting = 1 mark change in potential energy = 0 marks gravitational potential energy = 1 mark
5. Annotations: The following annotations are available on SCORIS.
= correct response = incorrect response bod = benefit of the doubt nbod = benefit of the doubt not given ECF = error carried forward ^ = information omitted I = ignore R = reject
6. If a candidate alters his/her response, examiners should accept the alteration.
7. Crossed out answers should be considered only if no other response has been made. When marking crossed out responses, accept correct answers which are clear and unambiguous.
1
A323/02 Mark Scheme June 2010
2
E.g. For a one mark question, where ticks in boxes 3 and 4 are required for the mark:
Put ticks () in the two correct boxes.
This would be worth 0 marks.
Put ticks () in the two correct boxes.
This would be worth one mark.
Put ticks () in the two correct boxes.
This would be worth one mark.
8. The list principle: If a list of responses greater than the number requested is given, work through the list from the beginning. Award one mark for each correct response, ignore any neutral response, and deduct one mark for any incorrect response, e.g. one which has an error of science. If the number of incorrect responses is equal to or greater than the number of correct responses, no marks are awarded. A neutral response is correct but irrelevant to the question.
9. Marking method for tick boxes:
Always check the additional guidance.
If there is a set of boxes, some of which should be ticked and others left empty, then judge the entire set of boxes. If there is at least one tick, ignore crosses. If there are no ticks, accept clear, unambiguous indications, e.g. shading or crosses. Credit should be given for each box correctly ticked. If more boxes are ticked than there are correct answers, then deduct one mark for each additional tick. Candidates cannot score less than zero marks.
E.g. If a question requires candidates to identify a city in England, then in the boxes
Edinburgh Manchester Paris Southampton
the second and fourth boxes should have ticks (or other clear indication of choice) and the first and third should be blank (or have indication of choice crossed out).
Edinburgh Manchester × Paris Southampton × Score: 2 2 1 1 1 1 0 0 0 NR
A323/02 Mark Scheme June 2010
Question Expected Answer Mark Additional Guidance 1 a any two from:
reference to using fertilisers (1) reference to using pesticides (1) cotton is bleached (using harmful chemicals) (1)
[2]
b they are easier to use/more convenient / they do not need to be washed / they are kinder to a baby's skin (1)
[1] allow more comfortable for baby / less likely to leak do not allow economy answers
c from getting the raw material used to make the product to the disposal of the product (1)
[1] do not allow answers that start from making product from raw material
d description: electricity/detergent used for washing (1) explanation: generating electricity causes pollution / detergent released into rivers etc (1)
[2] allow use of energy instead electricity allow any reasonable explanation of how this causes environmental impact
e not everyone would collect used nappies for recycling / may be difficult to collect all used nappies (1) there are not enough recycling plants available / so many nappies are used that this would be difficult (1) there may not be enough demand for the materials produced by recycling (1)
[3] three areas for marks: collection huge volume demand for products
f i forces (of attraction) between polymer chains/molecules are low (1) so little energy is needed to separate the chains/molecules (1)
[2] for the first mark candidates must write about forces between chains/molecules not bonds for second mark allow reference to breaking bonds between chains/molecules as long as energy mentioned ignore references to short chains
ii decrease chain length / decrease crystallisation / add plasticizer / decrease density (1) to decrease forces/attraction between chains/molecules (1)
[2] allow make branched polymer allow decreases number/strength of bonds between chains/molecules ignore references to less energy needed
Total [13]
3
A323/02 Mark Scheme June 2010
Question Expected Answer Mark Additional Guidance
2 a sodium + ethanol (slow) fizzing / dissolves / gets smaller / moves slowly across the surface (1) sodium + water (fast) fizzing / dissolves (quickly) / gets smaller (quickly) / shoots around on surface / melts / produces flame (1) sodium + hexane no reaction (1) answer shows that reaction with water is more vigorous than that with ethanol (1)
[4] one mark each for a valid observation for each of the three demonstrations if a mixture of valid and non-valid observations are made this loses the mark for that box plus one additional mark for a correct comparison of the same observation with ethanol and with water allow bubbling=fizzing=hydrogen/gas given off
b similarity: ethanol and water have O-H group/same functional group/oxygen and so react in a similar way (1) difference: hexane has only carbon and hydrogen atoms/does not have an O-H group/does not have oxygen and so does not react (1)
[2] allow water and ethanol have polar bonds allow hexane is a hydrocarbon/has unreactive C-C and C-H bonds and so does not react to score the answers must refer to the reactions not just to the structures
c i (high concentration of) ethanol kills yeast (1) [1] allow the ethanol denatures/destroys the yeast allow ethanol denatures enzymes but do not allow kills enzymes
ii distillation (1) plus any two from: mixture is heated/evaporated/boiled (1) vapour cooled to condense it (1) ethanol has lower/different boiling point (so is collected on its own/separately) (1)
[3] allow fractional distillation allow explanation marks independent of name but do not give marks for a method that does not separate eg reflux ignore ethanol has low boiling point
Total [10]
4
A323/02 Mark Scheme June 2010
Question Expected Answer Mark Additional Guidance
3 a energy level of reactants is higher than that of products (1) so energy/heat given out during the reaction (1)
[2] allow energy level at end is lower than at beginning / energy level goes down / energy change is negative
b energy needed to start a reaction (1) energy needed to break bonds (1)
[2] allow first mark for energy needed for a reaction to take place/begin / energy needed for successful collisions ignore reference to catalysts
c i (2 x 805 =) 1610 (1) (4 x 464 =) 1856 (1) energy released = 3466 (1)
[3] allow 3 marks for 3466 without working (even if not on answer line) ignore if go on to calculate 730 here
ii 730 (1) [1] ignore sign (plus or minus) allow ecf from ci give mark for 730 without working
Total [8] 4 a i 4.8 (1)
divided by 7.0 = 0.69 (1) [2] give 2 marks for correct answer without working
do not allow 4.9 or 0.7 allow 0.68 or 0.685 or 0.686 (max 3 sf)
ii Rf value is always the same for each compound (1) distance travelled by spot/solvent front may be different on different chromatograms (1)
[2] allow can be used to identify compound ignore reference to accuracy/precision
b stationary phase is paper and mobile phase is solvent / mobile phase moves up through stationary phase (1) for each compound there is a dynamic equilibrium between the two phases (1) how far each compound moves depends on its distribution between the two phases / if the compound is more soluble in the mobile phase it will move further up the paper (1)
[3] for third mark allow compounds travel different distances because they have different solubility in phases / dynamic equilibrium is more to one side / spend different amounts of time in the two phases
Total [7]
5
A323/02 Mark Scheme June 2010
6
Question Expected Answer Mark Additional Guidance
5 a measure out 25.0 cm3 of the stock solution (1) make up to 250 cm3 with (distilled/deionised) water (1)
[2] allow one mark for adding 1 part stock solution to 9 parts water ignore references to dilution to a tenth of stock concentration
b i 28.2 x 6.3/1000 = 0.178 (1) [1] be careful not to give this mark just for getting 0.178 the mark is for the correct method used to get 0.178 do not allow a mark for eg 28.2 x 6.3/100 = 0.178
ii 0.178 x 40/63 (1) = 0.113 (1) 0.113 x 1000/25 = 4.52 (1)
[3] allow any correct method for working eg 40 x 6.3/63 x 28.2/1000 allow 0.113 without working for 2 marks allow ecf from mass to concentration ie x40
iii uncertainty is low / value is reliable (1) because titration results show little variation/are very close/are within 0.2/have small range (1)
[2] ignore references to accuracy ignore references to outliers
Total [8] 6 a air makes the process (more) sustainable (1)
because the supply of air is not limited / air is renewable (1) natural gas makes the process less/not sustainable (1) because it is finite/will one day run out/not renewable (1)
[4]
b catalyst provides an alternative route (1) with a lower activation energy / less energy needed to begin the reaction / less energy needed to break bonds (1) QWC is for correct use of the term activation energy (1)
[2]
[1]
do not allow marks for other explanations of how a catalyst works ignore references to collisions
c reactants/nitrogen and hydrogen that have not reacted are recycled (1) ammonia is removed so the system does not reach equilibrium/reverse reaction is not possible/pushes equilibrium to the right (1)
[2] no mark simply for saying 85% recycled, must have idea that this gas has not reacted / goes back to react
Total [9]
OCR (Oxford Cambridge and RSA Examinations) 1 Hills Road Cambridge CB1 2EU OCR Customer Contact Centre 14 – 19 Qualifications (General) Telephone: 01223 553998 Facsimile: 01223 552627 Email: [email protected] www.ocr.org.uk For staff training purposes and as part of our quality assurance programme your call may be recorded or monitored
TWENTY FIRST CENTURY SCIENCE A323/01CHEMISTRY AUnit 3: Ideas in Context plus C7(Foundation Tier)
F
INSTRUCTIONS TO CANDIDATES
• Write your name clearly in capital letters, your Centre Number and Candidate Number in the boxes above.• Use black ink. Pencil may be used for graphs and diagrams only.• Read each question carefully and make sure that you know what you have to do before starting your answer.• Answer all the questions.• Do not write in the bar codes.• Write your answer to each question in the space provided, however additional paper may be used if
necessary.
INFORMATION FOR CANDIDATES
• The number of marks is given in brackets [ ] at the end of each question or part question.• The total number of marks for this paper is 55.• Where you see this icon you will be awarded a mark for the quality of written communication in
your answer.
• The Periodic Table is printed on the back page.• This document consists of 16 pages. Any blank pages are indicated.
(b) (i) When an ester is hydrolysed it forms an alcohol and a carboxylic acid. This reaction is the reverse of that used to make the ester.
Oils and fats are esters. Write the name of the alcohol and of the type of carboxylic acid to complete this word equation for the hydrolysis of an oil.
oil + water .......................................... + .......................................... [2]
(ii) What two things does the sign tell you about this reaction?
5 Some indigestion tablets contain the active ingredient, magnesium hydroxide. This reacts with excess stomach acid to relieve the symptoms of acid indigestion.
Mg(OH)2 + 2HCl MgCl2 + 2H2O
The tablets also contain starch.
A chemist uses quantitative analysis to find the mass of active ingredient in each tablet.
(a) The statements describe the main stages of this analysis, but they are in the wrong order.
A Crush the tablet and stir it into approximately 25 cm3 distilled water.
B Use the average titration result to calculate the mass of magnesium hydroxide in each tablet.
C Titrate the mixture against hydrochloric acid of known concentration.
D Measure accurately the mass of one indigestion tablet.
E Estimate the degree of uncertainty in the result.
F Repeat the procedure using several more tablets.
Write letters in the boxes to show the correct order of the stages. The correct letter has already been written in the first box.
D
[3]
(b) What apparatus should the chemist use to measure each of the following?
OCR is committed to seeking permission to reproduce all third-party content that it uses in its assessment materials. OCR has attempted to identify and contact all copyright holders whose work is used in this paper. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced in the OCR Copyright Acknowledgements Booklet. This is produced for each series of examinations, is given to all schools that receive assessment material and is freely available to download from our public website (www.ocr.org.uk) after the live examination series.
If OCR has unwittingly failed to correctly acknowledge or clear any third-party content in this assessment material, OCR will be happy to correct its mistake at the earliest possible opportunity.
For queries or further information please contact the Copyright Team, First Floor, 9 Hills Road, Cambridge CB2 1PB.
OCR is part of the Cambridge Assessment Group; Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
GCSE Twenty First Century Science – Chemistry A (J634)
MARK SCHEMES FOR THE UNITS
Unit/Content Page Guidance for Examiners 1
A321/01 Modules C1, C2, C3 Foundation Tier 3
A321/02 Modules C1, C2, C3 Higher Tier 12
A322/01 Modules C4, C5, C6 Foundation Tier 22
A322/02 Modules C4, C5, C6 Higher Tier 32
A323/01 Unit 3 Ideas in Context plus C7 Foundation Tier 42
A323/02 Unit 3 Ideas in Context plus C7 Higher Tier 46
Grade Thresholds 53
J634 Mark Scheme June 2009
1
Guidance for Examiners
Additional Guidance within any mark scheme takes precedence over the following guidance. 1. Mark strictly to the mark scheme.
2. Make no deductions for wrong work after an acceptable answer unless the mark scheme says otherwise.
3. Accept any clear, unambiguous response which is correct, eg mis-spellings if phonetically correct (but check additional guidance).
4. Abbreviations, annotations and conventions used in the detailed mark scheme:
/ = alternative and acceptable answers for the same marking point (1) = separates marking points not/reject = answers which are not worthy of credit ignore = statements which are irrelevant - applies to neutral answers allow/accept = answers that can be accepted (words) = words which are not essential to gain credit words = underlined words must be present in answer to score a mark ecf = error carried forward AW/owtte = alternative wording ORA = or reverse argument Eg mark scheme shows ‘work done in lifting/(change in) gravitational potential energy’ (1) work done = 0 marks work done lifting = 1 mark change in potential energy = 0 marks gravitational potential energy = 1 mark
5. If a candidate alters his/her response, examiners should accept the alteration.
6. Crossed out answers should be considered only if no other response has been made. When marking crossed out responses, accept correct answers which are clear and unambiguous.
J634 Mark Scheme June 2009
7. The list principle: If a list of responses greater than the number requested is given, work through the list from the beginning. Award one mark for each correct response, ignore any neutral response, and deduct one mark for any incorrect response, eg one which has an error of science. If the number of incorrect responses is equal to or greater than the number of correct responses, no marks are awarded. A neutral response is correct but irrelevant to the question.
8. Marking method for tick boxes:
Always check the additional guidance.
If there is a set of boxes, some of which should be ticked and others left empty, then judge the entire set of boxes. If there is at least one tick, ignore crosses. If there are no ticks, accept clear, unambiguous indications, eg shading or crosses. Credit should be given for each box correctly ticked. If more boxes are ticked than there are correct answers, then deduct one mark for each additional tick. Candidates cannot score less than zero marks.
Eg If a question requires candidates to identify a city in England, then in the boxes
Edinburgh Manchester Paris Southampton
the second and fourth boxes should have ticks (or other clear indication of choice) and the first and third should be blank (or have indication
of choice crossed out).
Edinburgh Manchester × Paris Southampton × Score: 2 2 1 1 1 1 0 0 0 NR
2
A321/01 Mark Scheme June 2009
3
A321/01 Modules C1, C2, C3 Foundation Tier
Question Expected Answers Marks Rationale 1 a
nitrogen monoxide
CO
carbon
monoxide
NO
water vapour SO2
sulfur
dioxide H2O
4
Mark left and right hand sides independently Matching name to formula – two marks for all correct, one mark for two or three correct. (max 2) Matching formula to molecule – two marks for all correct, one mark for two or three correct (max 2) If 2 lines leave or arrive at one box then the mark is lost
b i sulfur dioxide/nitrogen monoxide/SO2/NO
1 either formula must be correct if used
ii carbon monoxide/CO
1 formula must be correct if used
iii water (vapour)/H2O
1 formula must be correct if used
Total 7
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 a
... reliable results (1)
1
3rd box
b i
... well outside the range ... (1)
1
2nd box
ii
... wind changed direction ... (1)
... burned less coal ... (1)
2
4th and 5th boxes
4
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 c 311;
297 to 322;
2 one mark for each correct answer accept 314/314.5/315 for the mean If 314/314.5/315 is given for the mean then allow 307 to 322 for the range Numbers for a range can be given in either order
d decreases decreases OR increases increases
1
both correct words required – (must be same word used twice)
Total 7
5
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a
... using the spoon (1)
1 3rd box
b
Supply of metal ores is finite. (1)
More trees can be planted ... (1)
Plastics made from crude oil ... (1)
3
2nd, 4th and 6th boxes
6
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 c
... metal spoon not stained... (1)
... plastic spoon too soft ... (1)
... wooden spoon stained ... (1)
3
2nd, 3rd and 5th boxes
Total 7
7
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 4 a
cotton polyester silk wool
1
correct word circled and no other words circled
b small; long; polymerisation;
3
one mark for each correct choice
c i
carbon (1)
hydrogen (1)
2
1st and 4th boxes
ii food fuels lubricants
1
Total 7
8
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 a i
Plants take nitrogen ... (1)
When crops are harvested ... (1)
2
2nd and 5th boxes
ii calcium carbon chlorine hydrogen neon oxygen sodium
2
all three correct words circled and no others circled for 2 marks two correct words circled for one mark marks are lost if more than three words are circled
b i Some crops naturally contain
toxic ... (1)
During storage, crops contaminated ... (1)
2 1st and 5th boxes
9
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 b ii
... safe levels of chemicals ... (1)
1 3rd box
Total 7
10
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 6 a
amino acids amino acids urine urea
4 one mark for each correct choice, correctly placed.
b
body no longer responds to its
own insulin
penicillin injections
type 1 insulin is
destroyed by the pancreas
diet and exercise
type 2 pancreas does
not produce enough insulin
insulin tablets
pancreas
produces too much insulin
insulin injections
2 one mark for each correct ‘row’ linking type of diabetes to both the correct description and the correct treatment More than one line leaving or arriving at a box loses the mark
c anorexia asthma obesity sunburn
1 one mark for the correct word and no other circled
Total 7
11
A321/02 Mark Scheme June 2009
12
A321/02 Modules C1, C2, C3 Higher Tier
Question Expected Answers Marks Rationale 1 a
sulfur dioxide SO2
nitrogen monoxide NO
carbon monoxide CO
3
one mark for each correct row do not allow SO2/So2/sO2
do not allow sulfur oxide/sulfur monoxide/sulfur trioxide allow sulfur(IV) oxide do not allow nitrogen oxide/nitrogen dioxide/nitrous oxide allow nitric oxide/nitrogen(II) oxide do not allow No/nO do not allow carbon oxide/carbon dioxide allow carbon(II) oxide do not allow Co/cO
b [1] [3] [2] [2]
3
one mark for each correct number after [1]
Total 6
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 a
... reliable results (1)
1
3rd box
b i
... well outside the range ... (1)
1
2nd box
ii
... wind changed direction ... (1)
... burned less coal ... (1)
2
4th and 5th boxes
13
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 c
... ranges don’t overlap. (1)
... mean before is outside range after ... (1)
2
3rd and 5th boxes
d i A (1)
1 no mark if two or more letters are quoted
ii D (1) 1 no mark if two or more letters are quoted
Total 8
14
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a
... using the spoon (1)
1 3rd box
b
Supply of metal ores is finite. (1)
More trees can be planted ... (1)
Plastics made from crude oil ... (1)
3
2nd, 4th and 6th boxes
15
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 c
... use and disposal ... (1)
... making the product from the material. (1)
2
2nd and 4th boxes
d
... available locally ...
It is easy to make wooden spoons ...
1
both 1st and 3rd boxes for one mark three or more boxes ticked = 0 marks
Total 7
16
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 4 a i B C D
1 one mark for any two of these three correct letters in any order
allow the mark if all three correct letters are given do not allow the mark if incorrect letter A is given
ii A D
1 one mark for both correct letters in either order do not allow the mark if more than two letters are given
iii A D
1 one mark for both correct letters in either order do not allow the mark if more than two letters are given
b
... less plasticizer ... (1)
Increase chain length ... (1)
2
1st and 5th boxes
c
... forces between the molecules.
… forces between the polymer chains stronger.
… but weak forces between …
2
all three of 1st, 4th and 5th boxes for two marks two boxes correct with or without a third incorrect one = one mark four boxes ticked = max one mark ie only gets the mark if all three correct boxes are included five or six boxes ticked = 0 marks
Total 7
17
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 a i
Plants take nitrogen ... (1)
When crops are harvested ... (1)
2 2nd and 5th boxes
ii carbon (1) and hydrogen (1)
2 one mark for each correct word, in either order for three words max 1 mark, for four words no marks for hydrogen allow H or H2 but not h or h2 for carbon allow C but not C2 etc
b i Some crops naturally contain
toxic ... (1)
During storage, crops contaminated ... (1)
2 1st and 5th boxes
18
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 b ii
... easier to make ...
... more expensive ...
1 both 1st and 3rd boxes for one mark three or more boxes ticked = 0 marks
Total 7
19
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 6 a amino acids
liver urea kidney(s) urine
3 all five words correct for 3 marks four words correct for 2 marks three words correct for 1 mark do not allow monomers for amino acids
b
... pancreas does not produce enough ...
Sugar ... is quickly absorbed ...
... to regulate the amount of sugar ...
2 all three of 2nd, 3rd and 6th boxes for two marks two boxes correct with or without a third one incorrect for one mark four boxes ticked = max one mark ie only gets the mark if all three correct boxes are included five or six boxes ticked = 0 marks
20
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 6 c
the chance ... contracting type 2 ... (1)
the consequences of ... diabetes (1)
2 2nd and 5th boxes
Total 7
21
A322/01 Mark Scheme June 2009
22
Question Expected Answers Marks Rationale 1 a
… reacts with cold water. … to form compounds. … quicker than potassium. … is very unstable.
2
all 4 correct = 2 2 or 3 correct = 1
1 correct = 0
Accept other indications of choice (eg lines or crosses)
b i protons (1) neutrons (1)
2
either order
ii 3 electrons arranged 2 inside the inner shell, 1 in the outer shell
1
Total 5
X
X
X
A322/01 Modules C4, C5, C6 Foundation Tier
false
true
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 a i
2 (1) mark for each correct line. If more than 2 lines are drawn, deduct (1) for each additional incorrect line.
ii
Do experiments in a fume cupboard. Do not breathe in the gas.
2 Accept other indications of choice (eg lines or crosses)
purple
dark grey
iodine gas
solid iodine
23
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 b
Iodine solution kills bacteria.
1 Accept other indications of choice (eg lines or crosses)
5
24
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a
the colour of the flame
1 Accept other indications of choice (eg lines or crosses)
b
a fixed pattern of lines
1 Accept other indications of choice (eg lines or crosses)
c
potassium (1) chlorine (1)
2 either order accept any phonetic spellings reject 'chloride'
Total 4
25
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
4 a 1 If more than 1 box is ticked, 0 marks
b C and H only in the formula (1) Fully correct formula: C2H4 (2)
2 C and H must be capitals eg Ch4 scores (0) C2h4 scores (1)
allow H4C2/CH2CH2/H2C2H2/H2CCH2
Any number in front of formula, can only score first mark eg
2CH2 scores (1)
2 and 4 must be clearly subscripted or smaller than C and H eg C2H4 or C2H4 scores (1)
Total 3
26
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
5 a i
more more less
2 all 3 correct = 2 1 or 2 correct = 1 Allow other indications of choice eg underlining
ii
50-65% (1)
1
b 2 all 3 correct = 2 1 or 2 correct = 1 If more than 3 lines are drawn, deduct (1) for each additional incorrect line.
Total 5
good
easily bent
very
property
gold
jewellery
car air
use
27
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
6 a
Bubbles form around an electrode. The bulb lights up.
2 If more than 2 boxes are ticked, deduct one mark for each additional tick
b ionic (1) ions (1) positive (1)
3
c lead (1)
1 Allow led Allow correct symbol Pb Do not allow PB
Total 6
28
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
7 a i sulfuric (acid)/sulphuric (acid) (1)
1 accept phonetic spelling
ii magnesium carbonate (1) magnesium oxide (1)
2 If more than two compounds are ringed, deduct (1) for each additional incorrect compound. Allow other indications of choice eg underlining
b
use acid that is more dilute
1 If more than 1 box is ticked, 0 marks
Total 4
29
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
8 a
indicator paper
1 If more than 1 box is ticked, 0 marks
b 3
Total 4
chemical acidic … pH
neutral
8-10
1-2
30
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
9 a 3
b neutralisation (1)
1 If more than one answer is ringed, deduct (1) for each additional incorrect response. Allow other indications of choice eg underlining
c i 40 (1)
1
ii
She spilled some chemicals.
1 If more than 1 box is ticked, 0 marks
Total 6
hydrochloric acid (1) burette (1)
flask (1)
31
A322/02 Mark Scheme June 2009
32
Question Expected Answers Marks Rationale 1 a
… reacts with cold water. … to form compounds. … quicker than potassium. … is very unstable.
2 all 4 correct = 2 2 or 3 correct = 1 1 correct = 0 Accept other indications of choice (eg lines or crosses)
b Correct symbols: Li and O2(1) Correct balancing: 4Li + O2 (1)
2 Must have capital L and lower case i in Li and capital O with subscripted 2 in O2. Do not allow LI Top of the number 2 in O2 should not be above half the height of the O, Do not allow O2. Second mark can only be scored if formulae are correct. Allow second mark if small errors in formula eg 4Li + O2 scores (1) Allow 4Li + 1 O2
Any other number in front of O2 does not score this mark.
Total 4
A322/02 Modules C4, C5, C6 Higher Tier
falsetrue
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 a i
2 (1) mark for each correct line. If more than 2 lines are drawn, deduct (1) for each additional incorrect line.
ii
2 (1) mark for each correct line. If more than 2 lines are drawn, deduct (1) for each additional incorrect line.
purple
dark grey
iodine gas
solid iodine
solid iodine
I2(g)
I2(s)
iodine gas
33
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 b
Iodine is in Group 7.
All Group 7 elements kill bacteria.
1 Both must be correct for (1) mark If more than two ticks, 0 marks
Total 5
34
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a
… light of different colours. … very hot and so emit light.
2 If more than two ticks are given, deduct (1) mark for each additional incorrect tick. Allow other indications of choice.
b protons and neutrons named in either order (1)
correct numbers of protons and neutrons: 4 protons, 5 neutrons (1)
4 electrons in arrangement 2,2 (1)
3
Second mark cannot be scored if protons and neutrons not named. 4 neutrons and 5 protons scores first mark only (1) Allow phonetic spelling of protons and neutrons. eg two electrons anywhere in each ‘ring’. Allow other symbols for electrons eg e, - or o
Total 5
X
X
X
X
35
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 4 a 1 If more than 1 box is ticked, 0 marks
b C and H only in the formula (1) Fully correct formula: C2H4 (2)
2 C and H must be capitals eg Ch4 scores (0) C2h4 scores (1) allow H4C2 / CH2CH2 / H2C2H2 / H2CCH2 Any number in front of formula, can only score first mark eg 2CH2 scores (1) 2 and 4 must be clearly subscripted or smaller than C and H eg C2H4 or C2H4 scores (1)
Total 3
36
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 a
Potassium iodide is an ionic compound. Ions in the liquid are free to move.
2 If more than two ticks are given, deduct (1) mark for each additional incorrect tick. Allow other indications of choice.
b lead (1)
1 Allow led Allow correct symbol Pb Do not allow PB
c e—/e 1 Do not allow word ‘electron’
Total 4
37
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 6 a C (1) 1 Allow lower case
More than one letter scores 0
b A (1) 1 As above
c D (1) 1 As above
d
Electrons are shared between atoms. The nucleus of each bonded atom …
2 If more than two ticks are given, deduct (1) mark for each additional incorrect tick. Allow other indications of choice.
e MgF2 (1) 1 Must have capital M and lower case g in Mg and full size F with subscripted 2. Do not allow MGF2/Mg2F/MgF2 /Mg2F /F2Mg Top of the number 2 after F should not be above half the height of the F, Do not allow MgF2. Do not allow if any number is in front of formula eg 2MgF2 scores 0
Total 6
38
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 7 a i sulfuric (acid)/sulphuric (acid) (1) 1 accept phonetic spelling
ii magnesium carbonate (1) magnesium oxide (1)
2 If more than two compounds are ringed, deduct (1) for each additional incorrect compound. Allow other indications of choice eg underlining
b i
All the acid is used up.
1 If more than 1 box is ticked, 0 marks
ii
to get more magnesium sulfate …
1 If more than 1 box is ticked, 0 marks
39
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 7 b iii
… largest crystals. …as he heats it. … faster the crystals form. … solid salt evaporate.
2 All 4 correct = 2 2 or 3 correct = 1 1 correct = 0
c
use acid that is more dilute
1 If more than 1 box is ticked, 0 marks
Total 8
true false
40
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 8 a i A (1) 1 If more than one choice ringed, 0 marks
ii B and C (1) 1 both needed for the mark If more than two letters ringed, 0 marks
b K+ ringed and both K22+ and K2+ unringed (1)
SO4
2— ringed and both S2- and O2- unringed (1)
2
c
… produces a precipitate. … is a neutralisation reaction. … produces OH— ions. An equation for the reaction is … Hydrogen gas is given off.
3 All 5 correct = 3 4 correct = 2 2 or 3 correct = 1 1 correct = 0
Total 7
true false
41
A323/01 Mark Scheme June 2009
42
A323/01 Unit 3 Ideas in Context plus C7 Foundation Tier
Question Expected Answers Marks Rationale 1 a i any two from:
corn; maize; sugar (beet);
1 both required for the mark
ii Austria (1) 1
b any two from: produces less carbon dioxide; requires less energy to produce; transport produces less pollution; it is sustainable; it is renewable; it is biodegradable; it is less toxic than fossil fuels; it produces less carbon monoxide/particulate carbon;
2
c i annual wheat surplus of 3.5 million tons would produce enough bioethanol for only about 5%/car engines will have to be modified to use more than 5% bioethanol/insufficient land space to produce the crop/use more wheat than surplus/reduces land space for food (1)
1
ii 20 hectares of wheat (1) 1
d i as more crops are grown for fuel less will be grown for food, causing a shortage (1)
1
ii fossil fuel will be used to produce the fertilizer (1) over use of fertilizer will cause water pollution (1)
2
A323/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 1 e i any two from:
(energy used in/environmental impact of:) growing fuel crop/harvesting fuel crop/fuel crop is renewable; fermentation/processing into ethanol; decrease in soil fertility; effect on water supply; use of fertilizers;
2 ignore renewable unqualified
e ii petrol/crude oil is finite/not renewable (1) bioethanol is made from crops, which we can grow more of (1)
2 allow description of carbon cycle for bioethanol allow bioethanol is renewable
Total 13 Question Expected Answers Marks Rationale 2 a circle around COOH group (1) 1
b i methanoic acid + calcium carbonate (1) → calcium methanoate + carbon dioxide + water (1)
2
ii calcium methanoate is soluble (1) 1
iii methanoic acid is a weak acid (1) hydrochloric is a strong acid (1) hydrochloric acid will damage the kettle/methanoic acid will remove limescale without damaging the kettle (1) QWC - at least ten words with no more than one spelling error (1)
4
c structure of CH3 correct (1) structure of COOH correct (1)
2
Total 10
H O H C C H O H
43
A323/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a as an energy store (1) 1
b i glycerol (1) + fatty acids (1) 2 either order allow long chain carboxylic acids = fatty acids
ii reaction is reversible/reaction can go either way/reaction can go forwards and backwards (1) reaction reaches an equilibrium/all reactants and products are present in the reaction mixture (at equilibrium) (1)
2 allow it is a (dynamic) equilibrium allow forward and reverse rates are the same
c as flavouring/to improve taste (1) to give the required smell/to improve smell (1)
2
Total 7 Question Expected Answers Marks Rationale 4 a time from injection of sample (1)
until chemical leaves column/to appearance of peak/is detected (1)
2 time it takes to go through stationary phase is 2 marks
b i ethane propene butane 2 any order all correct = 2 marks 2 correct 1= 1 mark reject propane
ii propene (1) 1 reject propane
iii propene (1) 1 reject propane
c i any two from: they have unreactive C-C bonds; they have unreactive C-H bonds; they only have single bonds/they do not have double bonds/they are saturated;
2 allow they have unreactive bonds for 1 mark only ignore all their bonds are strong/C-C bonds are stronger than C=C bonds
ii bond making releases energy and bond breaking takes in energy (1) more energy is released than taken in (1)
2 allow as alternative words exothermic = releases energy, endothermic = takes in energy marks can be scored from an annotated energy level diagram
Total 10
44
A323/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 a
D A C F B E
3 all 5 in correct order = 3 marks any 4 in correct order = 2 marks any 3 in correct order = 1 mark
b i measuring cylinder (1)
1 allow pipette
ii burette (1) 1
c i use of 24, 16 and 1 in calculation but processed incorrectly (1) 58 (1)
2 allow first mark for calculations otherwise correct but missing out a step eg 2 x 1 or 2 x 16 do not allow first mark for totally incorrect calculation eg 24 x 16 x 1 allow 2 marks for correct answer without working
ii 0.75 (1) 1 allow 0.747/0.746 allow ecf from 5(c)(i)
Total 8 Question Expected Answers Marks Rationale 6 a i a chemical made in large quantities (1)
1
ii it is made from ethene which is made from crude oil (1) crude oil/ethene is finite/crude oil/ethene will run out (1)
2
b i the calcium chloride must be dumped/the calcium chloride must be disposed of (1)
1 must imply that calcium chloride has to be disposed of – not just a waste product.
ii larger surface area (1) gives more contact with reactants (1)
2
c to protect people/to protect the environment/health and safety (1)
1 allow make safe allow harming others by misuse
Total 7
Paper Total 55
45
A323/02 Mark Scheme June 2009
46
A323/02 Unit 3 Ideas in Context plus C7 Higher Tier
Question Expected Answers Marks Rationale 1 a pollution is caused/carbon dioxide is released by the
production process (1) it gives 70% of the mileage of petrol (1)
2 allow as bioethanol is made = production process ignore releases 34% less energy unless qualified allow eg it gives less miles (per gallon) than petrol
b this would use wheat/land that is now used for food/cause decline in soil fertility/decrease water supply/quality/increase fertiliser use (1) food prices would increase/there would be a food shortage/we would have to import more food (1) car engines would need to be modified (1)
2 Any two ignore uses a lot of land/would use too much land ignore references to decreasing habitats for animals ignore would have to import bioethanol
c these countries struggle to feed everyone/ need all their crops for food (1) making bioethanol will cause a food shortage/cause famine (1)
2 ignore references to land quality/rainfall/technology/cars/ignore copied statement ‘The amount of grain …. an African village’.
d RFM octane 114 and RFM carbon dioxide 44 (1) mass of carbon dioxide = (8x44)/114 = 3.1 g (1) percentage = 100 x (3.1-1.9)/1.9 = 63 or percentage = [(3.1/1.9) x 100] – 100 = 63 (1)
3 allow 352 for 44 (ie 8 x 44) allow 2 marks for correct mass of carbon dioxide alone allow 3.08 g/3.09 g/3.087 g/3.088 g allow any answer between 62.0 and 63.2 but do not allow an answer that is derived from incorrect working allow ecf from mass answer for % from 55 to 65 only do not give mark for 60% unless working gives 3.04 for mass
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 1 e i (energy used in/environmental impact of:)
growing fuel crop/harvesting fuel crop/fuel crop is renewable; fermentation/processing into ethanol; decrease in soil fertility; effect on water supply; use of fertilisers;
2 Any two ignore renewable unqualified
ii petrol/crude oil is finite/not renewable (1) bioethanol is made from crops, which we can grow more of (1)
2 allow description of carbon cycle for bioethanol allow bioethanol is renewable
Total 13
47
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 a COOH 1 allow CO2H
O allow C OH
b i
CaCO3 + 2HCOOH Ca(HCOO)2 + CO2 + H2O
2
one mark for all formulae correct, one mark for balance balance mark can only be scored if formulae correct allow molecular formulae subscript numbers must be clearly subscript or no marks
ii calcium methanoate is soluble (1)
1
iii a strong acid is completely ionised (1) a weak acid is only partly ionised (1) the weak acid has dynamic equilibrium/in a weak acid the equilibrium is far to the left/in a dynamic equilibrium the reaction does not go to completion (1) QWC - at least ten words with no more than one spelling error per ten words (1)
4 only give the third marking point if there is no suggestion that the strong acid also has a (dynamic) equilibrium ignore reaction goes in both directions QWC mark can be given if there has been a genuine attempt at an answer even if the chemistry has scored no marks
c H H H O H C C C C H H H O H
1 allow CH3 for methyl group/CH3CH2CH2COOH allow COOH for carboxyl group/OH instead of O-H allow correct structure with a circle around each atom reject molecule drawings using shaded circles to show atoms
Total 9
48
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a i glycerol (1) + fatty acids (1)
2 either order
allow long chain carboxylic acids = fatty acids
ii reaction is reversible/reaction can go either way/reaction can go forwards and backwards (1) reaction reaches an equilibrium/all reactants and products are present in the reaction mixture (at equilibrium) (1)
2 allow it is a (dynamic) equilibrium allow forward and reverse rates are the same
b purification: product is shaken with reagent in a tap/separating funnel (1) impurities dissolve in reagent (which can be run off) (1) drying: solid drying agent is added to product (1) the drying agent absorbs water from the product (1)
4 allow named reagent eg distilled water ignore references to neutralisation allow named solid drying agent eg calcium chloride/sodium sulfate, do not allow calcium carbonate!
Total 8
49
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 4 a i propene
1 do not allow propane!
ii area under the peak is largest/area under peak shows concentration
1 allow highest/widest/longest ignore references to retention time
b the mobile phase carries the sample (1) components are differently attracted to the stationary and mobile phases (1) the components that are more strongly attracted to the stationary phase move more slowly/ora (1) the amount of each component in the stationary phase and in the mobile phase is determined by a dynamic equilibrium (1)
4 accept answers that are based on ideas of different concentrations/different time spent in each phase as alternative to attraction again accept answers that are based on ideas of different concentrations/different time spent in each phase as alternative to attraction
c i they have unreactive C-C bonds (1) they have unreactive C-H bonds (1) they only have single bonds/they do not have double bonds/they are saturated (1)
2 Any two allow they have unreactive bonds = 1 mark only ignore all their bonds are strong/C-C bonds are stronger than C=C bonds
ii bond making releases energy and bond breaking takes in energy (1) more energy is released than taken in (1)
2 allow as alternative words exothermic = releases energy , endothermic = takes in energy marks can be scored from an annotated energy level diagram
Total 10
50
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 a i use of 24, 16 and 1 in calculation but processed
incorrectly (1) 58 (1)
2 allow first mark for calculations otherwise correct but missing out a step eg 2x1 or 2x16 do not allow first mark for totally incorrect calculation eg 24x16x1 allow 2 marks for correct answer without working
ii (40 x 23.5/1000 =) 0.94 g
1
iii 58 x 0.94/73 (1) = 0.75 g (1)
2 allow 2 marks for correct answer without working allow 0.747 g/0.746 g but not 0.7 g or 0.8 g allow ecf from (i) and (ii) only if working shown
b there is only a small degree of uncertainty (1) all of the titration values are close to average/23.5/all titration values are within 0.1 of average/23.5/titration values have a small range/range of 0.2 (1)
2 ignore references to reliability (for first marking point) allow titration results are reliable
Total 7
51
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 6 a i both methods are not sustainable (1)
because feedstock/hydrocarbon/ethene obtained from crude oil which has a finite supply (1)
2
ii old method is less sustainable/ora (1) old method has a by-product/old method has worse atom economy unless uses can be found for the by-product(1)
2 allow named by-product: calcium chloride
b catalyst provides an alternative route for the reaction (1) with a lower activation energy (1)
2 allow reactants stick to catalyst surface (1) increases concentration of reactants (1) allow interaction with catalyst breaks/weakens bonds of reactants (1) allowing products to be formed faster (1) ignore references to collision rate or increased surface area
c 2C2H4 + O2 2(CH2)2O
2
one mark for correct formulae, one mark for balance allow C2H4O for epoxyethane allow displayed formulae if correct balance mark can only be scored if formulae correct subscript numbers must be clearly subscript or no marks
Total 8
Paper Total 55
52
53
Grade Thresholds
General Certificate of Secondary Education Chemistry A (Specification Code J634) June 2009 Examination Series Unit Threshold Marks
A329/A330 (Coursework) - The grade thresholds have been determined on the basis of the work that was presented for award in June 2009. The threshold marks will not necessarily be the same in subsequent awards. Specification Aggregation Results Overall threshold marks in UMS (ie after conversion of raw marks to uniform marks) Maximum
Mark A* A B C D E F G U
J634 300 270 240 210 180 150 120 90 60 0 The cumulative percentage of candidates awarded each grade was as follows:
A* A B C D E F G U Total No. of Cands
J634 20.3 47.6 76.0 93.6 98.9 99.8 100.0 100.0 100.0 15121 15456 candidates were entered for aggregation this series For a description of how UMS marks are calculated see: http://www.ocr.org.uk/learners/ums_results.html Statistics are correct at the time of publication.
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TWENTY FIRST CENTURY SCIENCE A323/02CHEMISTRY AUnit 3: Ideas in Context plus C7(Higher Tier)
H
INSTRUCTIONS TO CANDIDATES
• Write your name clearly in capital letters, your Centre Number and Candidate Number in the boxes above.• Use black ink. Pencil may be used for graphs and diagrams only.• Read each question carefully and make sure that you know what you have to do before starting your answer.• Answer all the questions.• Do not write in the bar codes.• Write your answer to each question in the space provided, however additional paper may be used if
necessary.
INFORMATION FOR CANDIDATES
• The number of marks is given in brackets [ ] at the end of each question or part question.• The total number of marks for this paper is 55.• Where you see this icon you will be awarded a mark for the quality of written communication in
your answer.
• The Periodic Table is printed on the back page.• This document consists of 16 pages. Any blank pages are indicated.
1 This question is based on the article ‘The bioethanol dilemma’.
(a) Burning bioethanol gives a 70% carbon dioxide reduction compared to petrol.
However, some scientists think that the overall effect of using bioethanol instead of petrol would reduce total carbon dioxide emissions by only about 13%.
Use information from the article to explain why a figure of 13% for overall reduction in carbon dioxide emissions may be more realistic than 70%.
(d) The combustion of bioethanol can be represented by this equation.
C2H5OH + 3O2 2CO2 + 3H2O
Octane, C8H18, is one of the hydrocarbons in petrol. The combustion of octane can be represented by this equation.
C8H18 + 12½O2 8CO2 + 9H2O
Burning 1.0 g of bioethanol produces 1.9 g of carbon dioxide.
Burning octane produces about 60% more carbon dioxide than the same mass of bioethanol.
Show that this is true by calculating the mass of carbon dioxide produced when 1.0 g of octane burns, and the percentage increase in carbon dioxide produced compared to bioethanol.
(relative atomic masses: C = 12, H = 1, O = 16)
mass of carbon dioxide = ............................................................ g
3 Vegetable oils are commonly used in cooking. Examples are rape seed oil and sunflower seed oil.
(a) (i) When an ester is hydrolysed it forms an alcohol and a carboxylic acid. This reaction is the reverse of that used to make the ester.
Oils and fats are esters. Write the name of the alcohol and of the type of carboxylic acid to complete this word equation for the hydrolysis of an oil.
oil + water .......................................... + .......................................... [2]
(ii) What two things does the sign tell you about this reaction?
(b) An ester can be made by reacting an alcohol with a carboxylic acid. The technique used involves four stages: reflux, distillation, purification and drying.
In the reflux stage the alcohol and ester are heated with a little concentrated sulfuric acid in a flask with a condenser attached. The condenser prevents evaporation of the mixture.
In the distillation stage the mixture is heated, and the product collected at its boiling point. This separates the product from most of the impurities.
5 Some indigestion tablets contain the active ingredient, magnesium hydroxide. This neutralises excess stomach acid to relieve the symptoms of acid indigestion. The tablets also contain starch.
A chemist uses quantitative analysis to find the mass of active ingredient in each tablet. He makes a suspension of each of five tablets and titrates these with a solution containing hydrochloric acid. The concentration of this acid is 40.0 g / dm3.
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For queries or further information please contact the Copyright Team, First Floor, 9 Hills Road, Cambridge CB2 1PB.
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GCSE Twenty First Century Science – Chemistry A (J634)
MARK SCHEMES FOR THE UNITS
Unit/Content Page Guidance for Examiners 1
A321/01 Modules C1, C2, C3 Foundation Tier 3
A321/02 Modules C1, C2, C3 Higher Tier 12
A322/01 Modules C4, C5, C6 Foundation Tier 22
A322/02 Modules C4, C5, C6 Higher Tier 32
A323/01 Unit 3 Ideas in Context plus C7 Foundation Tier 42
A323/02 Unit 3 Ideas in Context plus C7 Higher Tier 46
Grade Thresholds 53
J634 Mark Scheme June 2009
1
Guidance for Examiners
Additional Guidance within any mark scheme takes precedence over the following guidance. 1. Mark strictly to the mark scheme.
2. Make no deductions for wrong work after an acceptable answer unless the mark scheme says otherwise.
3. Accept any clear, unambiguous response which is correct, eg mis-spellings if phonetically correct (but check additional guidance).
4. Abbreviations, annotations and conventions used in the detailed mark scheme:
/ = alternative and acceptable answers for the same marking point (1) = separates marking points not/reject = answers which are not worthy of credit ignore = statements which are irrelevant - applies to neutral answers allow/accept = answers that can be accepted (words) = words which are not essential to gain credit words = underlined words must be present in answer to score a mark ecf = error carried forward AW/owtte = alternative wording ORA = or reverse argument Eg mark scheme shows ‘work done in lifting/(change in) gravitational potential energy’ (1) work done = 0 marks work done lifting = 1 mark change in potential energy = 0 marks gravitational potential energy = 1 mark
5. If a candidate alters his/her response, examiners should accept the alteration.
6. Crossed out answers should be considered only if no other response has been made. When marking crossed out responses, accept correct answers which are clear and unambiguous.
J634 Mark Scheme June 2009
7. The list principle: If a list of responses greater than the number requested is given, work through the list from the beginning. Award one mark for each correct response, ignore any neutral response, and deduct one mark for any incorrect response, eg one which has an error of science. If the number of incorrect responses is equal to or greater than the number of correct responses, no marks are awarded. A neutral response is correct but irrelevant to the question.
8. Marking method for tick boxes:
Always check the additional guidance.
If there is a set of boxes, some of which should be ticked and others left empty, then judge the entire set of boxes. If there is at least one tick, ignore crosses. If there are no ticks, accept clear, unambiguous indications, eg shading or crosses. Credit should be given for each box correctly ticked. If more boxes are ticked than there are correct answers, then deduct one mark for each additional tick. Candidates cannot score less than zero marks.
Eg If a question requires candidates to identify a city in England, then in the boxes
Edinburgh Manchester Paris Southampton
the second and fourth boxes should have ticks (or other clear indication of choice) and the first and third should be blank (or have indication
of choice crossed out).
Edinburgh Manchester × Paris Southampton × Score: 2 2 1 1 1 1 0 0 0 NR
2
A321/01 Mark Scheme June 2009
3
A321/01 Modules C1, C2, C3 Foundation Tier
Question Expected Answers Marks Rationale 1 a
nitrogen monoxide
CO
carbon
monoxide
NO
water vapour SO2
sulfur
dioxide H2O
4
Mark left and right hand sides independently Matching name to formula – two marks for all correct, one mark for two or three correct. (max 2) Matching formula to molecule – two marks for all correct, one mark for two or three correct (max 2) If 2 lines leave or arrive at one box then the mark is lost
b i sulfur dioxide/nitrogen monoxide/SO2/NO
1 either formula must be correct if used
ii carbon monoxide/CO
1 formula must be correct if used
iii water (vapour)/H2O
1 formula must be correct if used
Total 7
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 a
... reliable results (1)
1
3rd box
b i
... well outside the range ... (1)
1
2nd box
ii
... wind changed direction ... (1)
... burned less coal ... (1)
2
4th and 5th boxes
4
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 c 311;
297 to 322;
2 one mark for each correct answer accept 314/314.5/315 for the mean If 314/314.5/315 is given for the mean then allow 307 to 322 for the range Numbers for a range can be given in either order
d decreases decreases OR increases increases
1
both correct words required – (must be same word used twice)
Total 7
5
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a
... using the spoon (1)
1 3rd box
b
Supply of metal ores is finite. (1)
More trees can be planted ... (1)
Plastics made from crude oil ... (1)
3
2nd, 4th and 6th boxes
6
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 c
... metal spoon not stained... (1)
... plastic spoon too soft ... (1)
... wooden spoon stained ... (1)
3
2nd, 3rd and 5th boxes
Total 7
7
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 4 a
cotton polyester silk wool
1
correct word circled and no other words circled
b small; long; polymerisation;
3
one mark for each correct choice
c i
carbon (1)
hydrogen (1)
2
1st and 4th boxes
ii food fuels lubricants
1
Total 7
8
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 a i
Plants take nitrogen ... (1)
When crops are harvested ... (1)
2
2nd and 5th boxes
ii calcium carbon chlorine hydrogen neon oxygen sodium
2
all three correct words circled and no others circled for 2 marks two correct words circled for one mark marks are lost if more than three words are circled
b i Some crops naturally contain
toxic ... (1)
During storage, crops contaminated ... (1)
2 1st and 5th boxes
9
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 b ii
... safe levels of chemicals ... (1)
1 3rd box
Total 7
10
A321/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 6 a
amino acids amino acids urine urea
4 one mark for each correct choice, correctly placed.
b
body no longer responds to its
own insulin
penicillin injections
type 1 insulin is
destroyed by the pancreas
diet and exercise
type 2 pancreas does
not produce enough insulin
insulin tablets
pancreas
produces too much insulin
insulin injections
2 one mark for each correct ‘row’ linking type of diabetes to both the correct description and the correct treatment More than one line leaving or arriving at a box loses the mark
c anorexia asthma obesity sunburn
1 one mark for the correct word and no other circled
Total 7
11
A321/02 Mark Scheme June 2009
12
A321/02 Modules C1, C2, C3 Higher Tier
Question Expected Answers Marks Rationale 1 a
sulfur dioxide SO2
nitrogen monoxide NO
carbon monoxide CO
3
one mark for each correct row do not allow SO2/So2/sO2
do not allow sulfur oxide/sulfur monoxide/sulfur trioxide allow sulfur(IV) oxide do not allow nitrogen oxide/nitrogen dioxide/nitrous oxide allow nitric oxide/nitrogen(II) oxide do not allow No/nO do not allow carbon oxide/carbon dioxide allow carbon(II) oxide do not allow Co/cO
b [1] [3] [2] [2]
3
one mark for each correct number after [1]
Total 6
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 a
... reliable results (1)
1
3rd box
b i
... well outside the range ... (1)
1
2nd box
ii
... wind changed direction ... (1)
... burned less coal ... (1)
2
4th and 5th boxes
13
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 c
... ranges don’t overlap. (1)
... mean before is outside range after ... (1)
2
3rd and 5th boxes
d i A (1)
1 no mark if two or more letters are quoted
ii D (1) 1 no mark if two or more letters are quoted
Total 8
14
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a
... using the spoon (1)
1 3rd box
b
Supply of metal ores is finite. (1)
More trees can be planted ... (1)
Plastics made from crude oil ... (1)
3
2nd, 4th and 6th boxes
15
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 c
... use and disposal ... (1)
... making the product from the material. (1)
2
2nd and 4th boxes
d
... available locally ...
It is easy to make wooden spoons ...
1
both 1st and 3rd boxes for one mark three or more boxes ticked = 0 marks
Total 7
16
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 4 a i B C D
1 one mark for any two of these three correct letters in any order
allow the mark if all three correct letters are given do not allow the mark if incorrect letter A is given
ii A D
1 one mark for both correct letters in either order do not allow the mark if more than two letters are given
iii A D
1 one mark for both correct letters in either order do not allow the mark if more than two letters are given
b
... less plasticizer ... (1)
Increase chain length ... (1)
2
1st and 5th boxes
c
... forces between the molecules.
… forces between the polymer chains stronger.
… but weak forces between …
2
all three of 1st, 4th and 5th boxes for two marks two boxes correct with or without a third incorrect one = one mark four boxes ticked = max one mark ie only gets the mark if all three correct boxes are included five or six boxes ticked = 0 marks
Total 7
17
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 a i
Plants take nitrogen ... (1)
When crops are harvested ... (1)
2 2nd and 5th boxes
ii carbon (1) and hydrogen (1)
2 one mark for each correct word, in either order for three words max 1 mark, for four words no marks for hydrogen allow H or H2 but not h or h2 for carbon allow C but not C2 etc
b i Some crops naturally contain
toxic ... (1)
During storage, crops contaminated ... (1)
2 1st and 5th boxes
18
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 b ii
... easier to make ...
... more expensive ...
1 both 1st and 3rd boxes for one mark three or more boxes ticked = 0 marks
Total 7
19
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 6 a amino acids
liver urea kidney(s) urine
3 all five words correct for 3 marks four words correct for 2 marks three words correct for 1 mark do not allow monomers for amino acids
b
... pancreas does not produce enough ...
Sugar ... is quickly absorbed ...
... to regulate the amount of sugar ...
2 all three of 2nd, 3rd and 6th boxes for two marks two boxes correct with or without a third one incorrect for one mark four boxes ticked = max one mark ie only gets the mark if all three correct boxes are included five or six boxes ticked = 0 marks
20
A321/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 6 c
the chance ... contracting type 2 ... (1)
the consequences of ... diabetes (1)
2 2nd and 5th boxes
Total 7
21
A322/01 Mark Scheme June 2009
22
Question Expected Answers Marks Rationale 1 a
… reacts with cold water. … to form compounds. … quicker than potassium. … is very unstable.
2
all 4 correct = 2 2 or 3 correct = 1
1 correct = 0
Accept other indications of choice (eg lines or crosses)
b i protons (1) neutrons (1)
2
either order
ii 3 electrons arranged 2 inside the inner shell, 1 in the outer shell
1
Total 5
X
X
X
A322/01 Modules C4, C5, C6 Foundation Tier
false
true
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 a i
2 (1) mark for each correct line. If more than 2 lines are drawn, deduct (1) for each additional incorrect line.
ii
Do experiments in a fume cupboard. Do not breathe in the gas.
2 Accept other indications of choice (eg lines or crosses)
purple
dark grey
iodine gas
solid iodine
23
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 b
Iodine solution kills bacteria.
1 Accept other indications of choice (eg lines or crosses)
5
24
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a
the colour of the flame
1 Accept other indications of choice (eg lines or crosses)
b
a fixed pattern of lines
1 Accept other indications of choice (eg lines or crosses)
c
potassium (1) chlorine (1)
2 either order accept any phonetic spellings reject 'chloride'
Total 4
25
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
4 a 1 If more than 1 box is ticked, 0 marks
b C and H only in the formula (1) Fully correct formula: C2H4 (2)
2 C and H must be capitals eg Ch4 scores (0) C2h4 scores (1)
allow H4C2/CH2CH2/H2C2H2/H2CCH2
Any number in front of formula, can only score first mark eg
2CH2 scores (1)
2 and 4 must be clearly subscripted or smaller than C and H eg C2H4 or C2H4 scores (1)
Total 3
26
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
5 a i
more more less
2 all 3 correct = 2 1 or 2 correct = 1 Allow other indications of choice eg underlining
ii
50-65% (1)
1
b 2 all 3 correct = 2 1 or 2 correct = 1 If more than 3 lines are drawn, deduct (1) for each additional incorrect line.
Total 5
good
easily bent
very
property
gold
jewellery
car air
use
27
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
6 a
Bubbles form around an electrode. The bulb lights up.
2 If more than 2 boxes are ticked, deduct one mark for each additional tick
b ionic (1) ions (1) positive (1)
3
c lead (1)
1 Allow led Allow correct symbol Pb Do not allow PB
Total 6
28
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
7 a i sulfuric (acid)/sulphuric (acid) (1)
1 accept phonetic spelling
ii magnesium carbonate (1) magnesium oxide (1)
2 If more than two compounds are ringed, deduct (1) for each additional incorrect compound. Allow other indications of choice eg underlining
b
use acid that is more dilute
1 If more than 1 box is ticked, 0 marks
Total 4
29
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
8 a
indicator paper
1 If more than 1 box is ticked, 0 marks
b 3
Total 4
chemical acidic … pH
neutral
8-10
1-2
30
A322/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale
9 a 3
b neutralisation (1)
1 If more than one answer is ringed, deduct (1) for each additional incorrect response. Allow other indications of choice eg underlining
c i 40 (1)
1
ii
She spilled some chemicals.
1 If more than 1 box is ticked, 0 marks
Total 6
hydrochloric acid (1) burette (1)
flask (1)
31
A322/02 Mark Scheme June 2009
32
Question Expected Answers Marks Rationale 1 a
… reacts with cold water. … to form compounds. … quicker than potassium. … is very unstable.
2 all 4 correct = 2 2 or 3 correct = 1 1 correct = 0 Accept other indications of choice (eg lines or crosses)
b Correct symbols: Li and O2(1) Correct balancing: 4Li + O2 (1)
2 Must have capital L and lower case i in Li and capital O with subscripted 2 in O2. Do not allow LI Top of the number 2 in O2 should not be above half the height of the O, Do not allow O2. Second mark can only be scored if formulae are correct. Allow second mark if small errors in formula eg 4Li + O2 scores (1) Allow 4Li + 1 O2
Any other number in front of O2 does not score this mark.
Total 4
A322/02 Modules C4, C5, C6 Higher Tier
falsetrue
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 a i
2 (1) mark for each correct line. If more than 2 lines are drawn, deduct (1) for each additional incorrect line.
ii
2 (1) mark for each correct line. If more than 2 lines are drawn, deduct (1) for each additional incorrect line.
purple
dark grey
iodine gas
solid iodine
solid iodine
I2(g)
I2(s)
iodine gas
33
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 b
Iodine is in Group 7.
All Group 7 elements kill bacteria.
1 Both must be correct for (1) mark If more than two ticks, 0 marks
Total 5
34
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a
… light of different colours. … very hot and so emit light.
2 If more than two ticks are given, deduct (1) mark for each additional incorrect tick. Allow other indications of choice.
b protons and neutrons named in either order (1)
correct numbers of protons and neutrons: 4 protons, 5 neutrons (1)
4 electrons in arrangement 2,2 (1)
3
Second mark cannot be scored if protons and neutrons not named. 4 neutrons and 5 protons scores first mark only (1) Allow phonetic spelling of protons and neutrons. eg two electrons anywhere in each ‘ring’. Allow other symbols for electrons eg e, - or o
Total 5
X
X
X
X
35
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 4 a 1 If more than 1 box is ticked, 0 marks
b C and H only in the formula (1) Fully correct formula: C2H4 (2)
2 C and H must be capitals eg Ch4 scores (0) C2h4 scores (1) allow H4C2 / CH2CH2 / H2C2H2 / H2CCH2 Any number in front of formula, can only score first mark eg 2CH2 scores (1) 2 and 4 must be clearly subscripted or smaller than C and H eg C2H4 or C2H4 scores (1)
Total 3
36
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 a
Potassium iodide is an ionic compound. Ions in the liquid are free to move.
2 If more than two ticks are given, deduct (1) mark for each additional incorrect tick. Allow other indications of choice.
b lead (1)
1 Allow led Allow correct symbol Pb Do not allow PB
c e—/e 1 Do not allow word ‘electron’
Total 4
37
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 6 a C (1) 1 Allow lower case
More than one letter scores 0
b A (1) 1 As above
c D (1) 1 As above
d
Electrons are shared between atoms. The nucleus of each bonded atom …
2 If more than two ticks are given, deduct (1) mark for each additional incorrect tick. Allow other indications of choice.
e MgF2 (1) 1 Must have capital M and lower case g in Mg and full size F with subscripted 2. Do not allow MGF2/Mg2F/MgF2 /Mg2F /F2Mg Top of the number 2 after F should not be above half the height of the F, Do not allow MgF2. Do not allow if any number is in front of formula eg 2MgF2 scores 0
Total 6
38
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 7 a i sulfuric (acid)/sulphuric (acid) (1) 1 accept phonetic spelling
ii magnesium carbonate (1) magnesium oxide (1)
2 If more than two compounds are ringed, deduct (1) for each additional incorrect compound. Allow other indications of choice eg underlining
b i
All the acid is used up.
1 If more than 1 box is ticked, 0 marks
ii
to get more magnesium sulfate …
1 If more than 1 box is ticked, 0 marks
39
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 7 b iii
… largest crystals. …as he heats it. … faster the crystals form. … solid salt evaporate.
2 All 4 correct = 2 2 or 3 correct = 1 1 correct = 0
c
use acid that is more dilute
1 If more than 1 box is ticked, 0 marks
Total 8
true false
40
A322/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 8 a i A (1) 1 If more than one choice ringed, 0 marks
ii B and C (1) 1 both needed for the mark If more than two letters ringed, 0 marks
b K+ ringed and both K22+ and K2+ unringed (1)
SO4
2— ringed and both S2- and O2- unringed (1)
2
c
… produces a precipitate. … is a neutralisation reaction. … produces OH— ions. An equation for the reaction is … Hydrogen gas is given off.
3 All 5 correct = 3 4 correct = 2 2 or 3 correct = 1 1 correct = 0
Total 7
true false
41
A323/01 Mark Scheme June 2009
42
A323/01 Unit 3 Ideas in Context plus C7 Foundation Tier
Question Expected Answers Marks Rationale 1 a i any two from:
corn; maize; sugar (beet);
1 both required for the mark
ii Austria (1) 1
b any two from: produces less carbon dioxide; requires less energy to produce; transport produces less pollution; it is sustainable; it is renewable; it is biodegradable; it is less toxic than fossil fuels; it produces less carbon monoxide/particulate carbon;
2
c i annual wheat surplus of 3.5 million tons would produce enough bioethanol for only about 5%/car engines will have to be modified to use more than 5% bioethanol/insufficient land space to produce the crop/use more wheat than surplus/reduces land space for food (1)
1
ii 20 hectares of wheat (1) 1
d i as more crops are grown for fuel less will be grown for food, causing a shortage (1)
1
ii fossil fuel will be used to produce the fertilizer (1) over use of fertilizer will cause water pollution (1)
2
A323/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 1 e i any two from:
(energy used in/environmental impact of:) growing fuel crop/harvesting fuel crop/fuel crop is renewable; fermentation/processing into ethanol; decrease in soil fertility; effect on water supply; use of fertilizers;
2 ignore renewable unqualified
e ii petrol/crude oil is finite/not renewable (1) bioethanol is made from crops, which we can grow more of (1)
2 allow description of carbon cycle for bioethanol allow bioethanol is renewable
Total 13 Question Expected Answers Marks Rationale 2 a circle around COOH group (1) 1
b i methanoic acid + calcium carbonate (1) → calcium methanoate + carbon dioxide + water (1)
2
ii calcium methanoate is soluble (1) 1
iii methanoic acid is a weak acid (1) hydrochloric is a strong acid (1) hydrochloric acid will damage the kettle/methanoic acid will remove limescale without damaging the kettle (1) QWC - at least ten words with no more than one spelling error (1)
4
c structure of CH3 correct (1) structure of COOH correct (1)
2
Total 10
H O H C C H O H
43
A323/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a as an energy store (1) 1
b i glycerol (1) + fatty acids (1) 2 either order allow long chain carboxylic acids = fatty acids
ii reaction is reversible/reaction can go either way/reaction can go forwards and backwards (1) reaction reaches an equilibrium/all reactants and products are present in the reaction mixture (at equilibrium) (1)
2 allow it is a (dynamic) equilibrium allow forward and reverse rates are the same
c as flavouring/to improve taste (1) to give the required smell/to improve smell (1)
2
Total 7 Question Expected Answers Marks Rationale 4 a time from injection of sample (1)
until chemical leaves column/to appearance of peak/is detected (1)
2 time it takes to go through stationary phase is 2 marks
b i ethane propene butane 2 any order all correct = 2 marks 2 correct 1= 1 mark reject propane
ii propene (1) 1 reject propane
iii propene (1) 1 reject propane
c i any two from: they have unreactive C-C bonds; they have unreactive C-H bonds; they only have single bonds/they do not have double bonds/they are saturated;
2 allow they have unreactive bonds for 1 mark only ignore all their bonds are strong/C-C bonds are stronger than C=C bonds
ii bond making releases energy and bond breaking takes in energy (1) more energy is released than taken in (1)
2 allow as alternative words exothermic = releases energy, endothermic = takes in energy marks can be scored from an annotated energy level diagram
Total 10
44
A323/01 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 a
D A C F B E
3 all 5 in correct order = 3 marks any 4 in correct order = 2 marks any 3 in correct order = 1 mark
b i measuring cylinder (1)
1 allow pipette
ii burette (1) 1
c i use of 24, 16 and 1 in calculation but processed incorrectly (1) 58 (1)
2 allow first mark for calculations otherwise correct but missing out a step eg 2 x 1 or 2 x 16 do not allow first mark for totally incorrect calculation eg 24 x 16 x 1 allow 2 marks for correct answer without working
ii 0.75 (1) 1 allow 0.747/0.746 allow ecf from 5(c)(i)
Total 8 Question Expected Answers Marks Rationale 6 a i a chemical made in large quantities (1)
1
ii it is made from ethene which is made from crude oil (1) crude oil/ethene is finite/crude oil/ethene will run out (1)
2
b i the calcium chloride must be dumped/the calcium chloride must be disposed of (1)
1 must imply that calcium chloride has to be disposed of – not just a waste product.
ii larger surface area (1) gives more contact with reactants (1)
2
c to protect people/to protect the environment/health and safety (1)
1 allow make safe allow harming others by misuse
Total 7
Paper Total 55
45
A323/02 Mark Scheme June 2009
46
A323/02 Unit 3 Ideas in Context plus C7 Higher Tier
Question Expected Answers Marks Rationale 1 a pollution is caused/carbon dioxide is released by the
production process (1) it gives 70% of the mileage of petrol (1)
2 allow as bioethanol is made = production process ignore releases 34% less energy unless qualified allow eg it gives less miles (per gallon) than petrol
b this would use wheat/land that is now used for food/cause decline in soil fertility/decrease water supply/quality/increase fertiliser use (1) food prices would increase/there would be a food shortage/we would have to import more food (1) car engines would need to be modified (1)
2 Any two ignore uses a lot of land/would use too much land ignore references to decreasing habitats for animals ignore would have to import bioethanol
c these countries struggle to feed everyone/ need all their crops for food (1) making bioethanol will cause a food shortage/cause famine (1)
2 ignore references to land quality/rainfall/technology/cars/ignore copied statement ‘The amount of grain …. an African village’.
d RFM octane 114 and RFM carbon dioxide 44 (1) mass of carbon dioxide = (8x44)/114 = 3.1 g (1) percentage = 100 x (3.1-1.9)/1.9 = 63 or percentage = [(3.1/1.9) x 100] – 100 = 63 (1)
3 allow 352 for 44 (ie 8 x 44) allow 2 marks for correct mass of carbon dioxide alone allow 3.08 g/3.09 g/3.087 g/3.088 g allow any answer between 62.0 and 63.2 but do not allow an answer that is derived from incorrect working allow ecf from mass answer for % from 55 to 65 only do not give mark for 60% unless working gives 3.04 for mass
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 1 e i (energy used in/environmental impact of:)
growing fuel crop/harvesting fuel crop/fuel crop is renewable; fermentation/processing into ethanol; decrease in soil fertility; effect on water supply; use of fertilisers;
2 Any two ignore renewable unqualified
ii petrol/crude oil is finite/not renewable (1) bioethanol is made from crops, which we can grow more of (1)
2 allow description of carbon cycle for bioethanol allow bioethanol is renewable
Total 13
47
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 2 a COOH 1 allow CO2H
O allow C OH
b i
CaCO3 + 2HCOOH Ca(HCOO)2 + CO2 + H2O
2
one mark for all formulae correct, one mark for balance balance mark can only be scored if formulae correct allow molecular formulae subscript numbers must be clearly subscript or no marks
ii calcium methanoate is soluble (1)
1
iii a strong acid is completely ionised (1) a weak acid is only partly ionised (1) the weak acid has dynamic equilibrium/in a weak acid the equilibrium is far to the left/in a dynamic equilibrium the reaction does not go to completion (1) QWC - at least ten words with no more than one spelling error per ten words (1)
4 only give the third marking point if there is no suggestion that the strong acid also has a (dynamic) equilibrium ignore reaction goes in both directions QWC mark can be given if there has been a genuine attempt at an answer even if the chemistry has scored no marks
c H H H O H C C C C H H H O H
1 allow CH3 for methyl group/CH3CH2CH2COOH allow COOH for carboxyl group/OH instead of O-H allow correct structure with a circle around each atom reject molecule drawings using shaded circles to show atoms
Total 9
48
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 3 a i glycerol (1) + fatty acids (1)
2 either order
allow long chain carboxylic acids = fatty acids
ii reaction is reversible/reaction can go either way/reaction can go forwards and backwards (1) reaction reaches an equilibrium/all reactants and products are present in the reaction mixture (at equilibrium) (1)
2 allow it is a (dynamic) equilibrium allow forward and reverse rates are the same
b purification: product is shaken with reagent in a tap/separating funnel (1) impurities dissolve in reagent (which can be run off) (1) drying: solid drying agent is added to product (1) the drying agent absorbs water from the product (1)
4 allow named reagent eg distilled water ignore references to neutralisation allow named solid drying agent eg calcium chloride/sodium sulfate, do not allow calcium carbonate!
Total 8
49
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 4 a i propene
1 do not allow propane!
ii area under the peak is largest/area under peak shows concentration
1 allow highest/widest/longest ignore references to retention time
b the mobile phase carries the sample (1) components are differently attracted to the stationary and mobile phases (1) the components that are more strongly attracted to the stationary phase move more slowly/ora (1) the amount of each component in the stationary phase and in the mobile phase is determined by a dynamic equilibrium (1)
4 accept answers that are based on ideas of different concentrations/different time spent in each phase as alternative to attraction again accept answers that are based on ideas of different concentrations/different time spent in each phase as alternative to attraction
c i they have unreactive C-C bonds (1) they have unreactive C-H bonds (1) they only have single bonds/they do not have double bonds/they are saturated (1)
2 Any two allow they have unreactive bonds = 1 mark only ignore all their bonds are strong/C-C bonds are stronger than C=C bonds
ii bond making releases energy and bond breaking takes in energy (1) more energy is released than taken in (1)
2 allow as alternative words exothermic = releases energy , endothermic = takes in energy marks can be scored from an annotated energy level diagram
Total 10
50
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 5 a i use of 24, 16 and 1 in calculation but processed
incorrectly (1) 58 (1)
2 allow first mark for calculations otherwise correct but missing out a step eg 2x1 or 2x16 do not allow first mark for totally incorrect calculation eg 24x16x1 allow 2 marks for correct answer without working
ii (40 x 23.5/1000 =) 0.94 g
1
iii 58 x 0.94/73 (1) = 0.75 g (1)
2 allow 2 marks for correct answer without working allow 0.747 g/0.746 g but not 0.7 g or 0.8 g allow ecf from (i) and (ii) only if working shown
b there is only a small degree of uncertainty (1) all of the titration values are close to average/23.5/all titration values are within 0.1 of average/23.5/titration values have a small range/range of 0.2 (1)
2 ignore references to reliability (for first marking point) allow titration results are reliable
Total 7
51
A323/02 Mark Scheme June 2009
Question Expected Answers Marks Rationale 6 a i both methods are not sustainable (1)
because feedstock/hydrocarbon/ethene obtained from crude oil which has a finite supply (1)
2
ii old method is less sustainable/ora (1) old method has a by-product/old method has worse atom economy unless uses can be found for the by-product(1)
2 allow named by-product: calcium chloride
b catalyst provides an alternative route for the reaction (1) with a lower activation energy (1)
2 allow reactants stick to catalyst surface (1) increases concentration of reactants (1) allow interaction with catalyst breaks/weakens bonds of reactants (1) allowing products to be formed faster (1) ignore references to collision rate or increased surface area
c 2C2H4 + O2 2(CH2)2O
2
one mark for correct formulae, one mark for balance allow C2H4O for epoxyethane allow displayed formulae if correct balance mark can only be scored if formulae correct subscript numbers must be clearly subscript or no marks
Total 8
Paper Total 55
52
53
Grade Thresholds
General Certificate of Secondary Education Chemistry A (Specification Code J634) June 2009 Examination Series Unit Threshold Marks
A329/A330 (Coursework) - The grade thresholds have been determined on the basis of the work that was presented for award in June 2009. The threshold marks will not necessarily be the same in subsequent awards. Specification Aggregation Results Overall threshold marks in UMS (ie after conversion of raw marks to uniform marks) Maximum
Mark A* A B C D E F G U
J634 300 270 240 210 180 150 120 90 60 0 The cumulative percentage of candidates awarded each grade was as follows:
A* A B C D E F G U Total No. of Cands
J634 20.3 47.6 76.0 93.6 98.9 99.8 100.0 100.0 100.0 15121 15456 candidates were entered for aggregation this series For a description of how UMS marks are calculated see: http://www.ocr.org.uk/learners/ums_results.html Statistics are correct at the time of publication.
OCR (Oxford Cambridge and RSA Examinations) 1 Hills Road Cambridge CB1 2EU OCR Customer Contact Centre 14 – 19 Qualifications (General) Telephone: 01223 553998 Facsimile: 01223 552627 Email: [email protected] www.ocr.org.uk For staff training purposes and as part of our quality assurance programme your call may be recorded or monitored
• Write your name in capital letters, your Centre Number and Candidate Number in the boxes above.• Use blue or black ink. Pencil may be used for graphs and diagrams only.• Read each question carefully and make sure that you know what you have to do before starting your
answer.• Answer all the questions.• Do not write in the bar codes.• Write your answer to each question in the space provided.
INFORMATION FOR CANDIDATES
• The number of marks for each question is given in brackets [ ] at the end of each question or part question.
• The total number of marks for this paper is 55.• The Periodic Table is printed on the back page.• Where you see this icon you will be awarded a mark for the
quality of written communication in your answer.
*CUP/T48789*
FOR EXAMINER’S USE
Qu. Max. Mark
1 13
2 12
3 10
4 10
5 10
TOTAL 55
GENERAL CERTIFICATE OF SECONDARY EDUCATION A323/01TWENTY FIRST CENTURY SCIENCE
CHEMISTRY AUnit 3 Ideas in Context plus C7 (Foundation Tier)
FRIDAY 23 MAY 2008 Afternoon
Time: 60 minutes
Candidates answer on the question paper.Additional materials (enclosed):Insert
Calculators may be used.Additional materials: Pencil Ruler (cm/mm)
2 Manufacturers around the world are trying to find alternative fuels to petrol and diesel. This will stop drivers using up the world’s fossil fuels. One alternative fuel is bio-ethanol, made by the fermentation of wheat or beet sugar.
Bio-ethanol can be mixed with petrol. When burned, this produces less carbon dioxide and other pollutants. Bio-ethanol also provides more energy and is a renewable energy source.
(a) Fermentation of carbohydrates by yeast produces a solution that is distilled to produce bio-ethanol.
(i) What are the optimum conditions for this fermentation?
Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (OCR) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.
OCR is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
GCSE Twenty First Century Science – Chemistry A (J634)
MARK SCHEMES FOR THE UNITS
Unit/Content Page Guidance for Examiners 1
A321/01 Modules C1, C2, C3 Foundation Tier 2
A321/02 Modules C1, C2, C3 Higher Tier 10
A322/01 Modules C4, C5, C6 Foundation Tier 18
A322/02 Modules C4, C5, C6 Higher Tier 23
A323/01 Ideas in Context and Unit C7 - Foundation 28
A323/02 Ideas in Context and Unit C7 - Higher 35
Grade Thresholds 43
1
Guidance for Examiners 1. Mark strictly to the mark scheme.
2. Make no deductions for wrong work after an acceptable answer unless the mark scheme says otherwise.
3. Each separate marking point is indicated by a (1) at the end of that marking point.
4. Abbreviations, annotations and conventions used in the detailed Mark Scheme:
ORA = or reverse argument NOT = point that is not given credit AW/owtte = alternative wording/or words to that effect: allow any expression that is clearly equivalent / = Alternative and acceptable answers for the same marking point point = point must be present to gain the mark (description) = description which need not be present to gain the mark
E.g. mark scheme shows ‘work done in lifting / (change in) gravitational potential energy’ work done = 0 marks work done lifting = 1 mark change in potential energy = 0 marks gravitational potential energy = 1 mark
5. If a candidate alters his/her response, examiners should accept the alteration.
6. The list principle: if a list of responses greater than the number requested is given, you work through the list from the beginning. Award one mark for each correct response, ignore any neutral response, and deduct one mark for any incorrect response, i.e. one which has an error of science. If the number of incorrect responses is equal to or greater than the number of correct responses, no marks are awarded. A neutral response is correct but irrelevant to the question.
7. Marking method for tick boxes: If there is a set of boxes, some of which should be ticked and others left empty, then you
need to judge the entire set of boxes.
E.g. If a question requires candidates to identify a city in England, then in the boxes
Edinburgh Manchester Paris Southampton
the second and fourth boxes should have ticks (or other clear indication of choice) and the
first and third should be blank (or have indication of choice crossed out). For a two-mark question, the rationale would be:
All boxes are indicated scores 0 marks. All boxes blank scores 0 marks. All four boxes correct scores 2 marks. Three boxes correct scores 1 mark. Two boxes correct scores 1 mark. Edinburgh Manchester × Paris Southampton × Score: 2 2 1 1 1 1 0 0 0 NR
A321/01 Mark Scheme June 2008
2
A321/01 Modules C1, C2, C3 Foundation Tier
Question Expected Answers Marks Rationale
1 a
each bus carries many people
many people travelling to work in cars make more total pollutants
1
both required
b
pollutantproblem caused
sulfur dioxide
( ) ( )
nitrogen oxides
(1)
carbon (1)
2
both ticks per correct line (1) ignore tick in third box on first line (sulfur dioxide)
c
carbon monoxide (1)
1
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
d i Joe 1 more than one choice ringed = 0 marks
ii Eve and Liz 1 both required more than two choices ringed = 0 marks
Total 6
3
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
2 a
name of gas percentage
oxygen (21%)
nitrogen (78%) (1)
argon (>1%) (1)
(carbon dioxide) (0.03%)
2
oxygen and nitrogen in the right order (1) argon (1)
b i
CO2 has increased rapidly over the last 200 years
(1)
before 1800, there were small changes in CO2
(1)
2
ii
there are many more motor vehicles in the world
(1)
1
4
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
2 c i
1
one of the two oxygen molecules circled (1) allow both oxygen molecules circled not circle around one oxygen atom only not circle that includes other molecules
ii
(1)
1
d
dissolving in rainwater
dissolving in the sea
plant photosynthesis
2
all three correct (2) two correct (1)
e carbon dioxide (1) water (1)
2
Total 11
5
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
3 a i ramie 1 more than one choice ringed = 0 marks
ii sisal
1 more than one choice ringed = 0 marks
iii
Hemp ropes do not absorb water as much
(1)
It is easier to handle light ropes
(1)
2
b i
check reliability (1) calculate a best estimate (1)
2
ii 800 to 1500 1 both required in either order
iii some of the rope was damp (1) natural materials vary widely (1)
2
6
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
3 c
strong and waterproof (1)
1
Total 10
4 a i poly(ethene)
1 more than one choice ringed = 0 marks
ii bakelite and melamine
1 both required more than two choices ringed = 0 marks
b crude oil (1) hydrogen and carbon (1)
2 both hydrogen and carbon required, in either order
Total 4
5 land produces more food per acre (1) food is larger and free of pests (1)
2
Total 2
7
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
6 a 2
all three choices correct (2) one or two choices correct (1) more than one line from the same box on the left to different boxes on the right is an incorrect choice
b additives passed safety test (1) approved for use in the UK (1)
2
Total 4
colouring
preservative
emulsifier
mix ingredients
look attractive
prevent microbes
8
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
7 a
women with BMI of 25 are 5 times more likely to have type 2 diabetes than BMI 22
(1)
reducing your BMI may reduce your risk of getting type 2 diabetes
(1)
2
b true false
3
all correct (3) four correct (2) two or three correct (1)
Total 5
Paper Total 42
9
A321/02 Mark Scheme June 2008
10
Question Expected Answers Marks Rationale 1 a i X marked on graph above 310 ppm 1 an indication of this position anywhere on the graph on or
above the line of 310 ppm but not above 370 ppm = 1 mark ii
increase of about 100 ppm (1)
increase of about 30% (1)
2
per correct tick (1)
b i
(1)
1
A321/02 Modules C1, C2, C3 Higher Tier
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 1 ii
3 all correct (3) three correct (2) two or one correct (1) more than one line leaving a box on the left or approaching a box on the right loses that mark.
Total 7
11
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 2 a
each bus carries many people
many people travelling to work in cars make more total pollutants
1
both required
b
pollutant problem caused
sulfur dioxide
( ) ( )
nitrogen oxides
(1)
carbon (1)
2
both ticks per correct line (1) ignore tick in third box on first line (sulfur dioxide)
c
incomplete combustion of the fuel (1)
1
12
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 2 d
true false N.E.EEve Joe Liz Sab
3
all correct (3) three correct (2) one or two correct (1)
e true false
2
all correct (2) two or three correct (1)
Total 9
13
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 3 a i hemp and sisal 1
both required
ii
ranges for the values overlap (1)
1
iii
Hemp ropes do not absorb water as much
(1)
It is easier to handle light ropes
(1)
2
b i
check reliability (1) calculate a best estimate (1)
2
ii flax is a natural material
range is too wide for average
1
both required
14
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 3 c
advantage disadvantage
2
all four correct (2) two or three correct (1)
Total 9
4 a i poly(ethene)
1 more than one choice ringed = 0 marks
ii bakelite and melamine
1 both required more than two choices ringed = 0 marks
b
… is more flexible … has a lower tensile strength … polymer chains further apart
2
all correct (2) two correct (1)
Total 4
15
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 5 a
wheat roots take up nutrients (1)
ripe wheat is harvested (1)
2
b true
intensive true
organic true both
3
all correct (3) four correct (2) two or three correct (1)
Total 5
6
D
D
C
B
3
all correct (3) three correct (2) one or two correct (1)
Total 3
16
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 7 a
women with BMI of 25 are 5 times more likely to have type 2 diabetes than BMI 22
(1)
reducing your BMI may reduce your risk of getting type 2 diabetes
(1)
2
b true false
3
all correct (3) four correct (2) two or three correct (1)
Total 5
Paper Total 42
17
A322/01 Mark Scheme June 2008
18
Question Expected Answers Marks Rationale 1 a Na (1)
K (1) 2 allow NA or na
b 3 per correctly joined right hand box (1) ensure that two lines are connected to the top right box; if one line is missing then lose one mark.
c i 3 six correctly joined pairs (3) five or four correctly joined pairs (2) three or two correctly joined pairs (1)
ii colourless 1
Total 9
black/purple
green
chlorine
bromine
solid
liquid
iodine gas orange/red
2.1
2.8.1
2.8.2
one electron in outer shell
two electrons in outer shell
three electrons in outer shell
2.8.3
A322/01 Modules C4, C5, C6 Foundation Tier
A322/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 2 a
elements compoundsoxygen carbon dioxide nitrogen water vapour
2 four rows correct (2) three or two rows correct (1) allow other clear identifying marks as well as ticks
b oxygen nitrogen carbon dioxide 1 all correct (1) allow incorrect spellings Allow symbols e.g. O/ O2 and N/N2 and CO2/CO2
Total 3
3 a
F
T
F
T
T
T
3 six correct (3) four or five correct (2) two or three correct (1) unmarked boxes are incorrect T or F must be clearly a T or an F rather than a combination or one overwritten on the other without clear decision. However, if the overwrite is clearly bolder, then allow.
b
bonds between particles are strong (1)
very large number of bonds (1)
2 if more than two boxes ticked then each extra box cancels a correct box
c Brenda (1) Daniel (1)
2 either order
Total 7
19
A322/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 4 a oxygen (1)
aluminium (1) 2 allow incorrect spellings
must be in this order not percentages
b compound 1
c sandstone 1
d mantle 1
Total 5
5 Carol (1) Delia (1)
2 either order
Total 2
6 impurities might have side effects (1) dose is the same every time (1) impossible to test new medicines (1)
3 per correct line (1) if more than three boxes ticked then each incorrect box cancels a correct box
Total 3
20
A322/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 7 a neutralisation
1
b 3 four correct lines (3) three or two correct lines (2) one correct line (1)
c reaction forms
a salt hydrogen gas water ( ) ( )
3 look at the question and all of the boxes as a whole. six correct boxes (3) five or four correct boxes (2) three or two correct boxes (1) one box correct scores zero
d sulfate (1) chloride (1)
2 allow sulphate, chloride/ chloride but no other incorrect spellings
e B 1 Allow H+ + OH-
21
A322/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 7 f
3 four correct lines (3)
three or two correct lines (2) one correct line (1)
Total 13
Paper Total 42
22
A322/02 Mark Scheme June 2008
23
A322/02 Modules C4, C5, C6 Higher Tier
Question Expected Answers Marks Rationale 1 Carol (1)
Delia (1)
2 either order
Total 2
2 a Brenda (1) Daniel (1)
2 either order
b MgCl21
c Li3N 1
d i
F
T
F
T
T
T
3 all correct (3) five or four correct (2) three or two correct (1) unmarked boxes are incorrect T or F must be clearly a T or an F rather than a combination or one overwritten on the other without clear decision. If overwrite is clearly bolder then allow.
ii bonds between particles are strong (1) very large number of bonds (1)
2 if more than two boxes ticked then each incorrect box cancels out a correct box
Total 9
A322/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 3 a
arrows 1 & 4 only (1)
1
b
arrow 1 only (1)
1
c i iodine and bromine (1) potassium and lithium (1) bromine (1)
3 allow any order allow any order
ii potassium and bromine 1 allow any order
24
A322/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 3 d
covalent ionic metallic
A
B
C
D
E
F
3 six rows correct (3) five or four correct (2) three or two correct (1) one correct (0) two ticks in one row = incorrect row
Total 9
4 B A C
2 three correct (2) two or one correct (1)
Total 2
5 impurities might have side effects (1) dose is the same every time (1) impossible to test new medicines (1)
3 per correct line (1) if more than three boxes ticked then each incorrect box cancels out a correct box
Total 3
25
A322/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 6 a Carl
1
b i 1g
1
ii 54g
1
Total 3
7 a B A F D E
2 all correct in correct order (2) C omitted from boxes, ABDEF in any order (1) Any answer that includes C scores 0
b i B
1
ii Al3+ + 3e- Al
1
iii arrow stays within the liquid and moves towards the right
1 If arrow goes to the left at any point then (0)
Total 5
26
A322/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 8 a Denise 1
b 2 for correct start point (1) for correct end point (1) more than one line (0)
Total 3
9 a H2SO4 + 2 NaOH Na2SO4 + 2 H2O
2 per correct answer (1)
b B 1 Allow H+ + OH-
c
3 (1) for each fully correct line if more than three lines then each extra incorrect lines cancels out a correct line
Total 6
Paper Total 42
There is lots of acid and lots of alkali.
There is lots of acid and no alkali.A
There is no acid and lots of alkali.C
There is no acid and no alkali.E
There is some acid and some alkali.
27
A323/01 Mark Scheme June 2008
28
A323/01 Ideas in Context and Unit C7 - Foundation
Question Expected Answers Marks Rationale 1 a i lithium
sodium potassium / chlorine bromine iodine
2 all three names correct (2) two correct names (1) allow any order three correct symbols (1)
ii for alkali metals: they are soft metals they are very reactive metals/react with water They float (on water) for halogens: they are gases they are very reactive non-metals
2 answer must match triad chosen in (i)
b any three from: it contained several major flaws Newlands assumed all elements had been discovered two elements placed in the same position elements with different properties in same group
3 maximum three
c example of three elements in positions 8 places apart (1) e.g. lithium, sodium and potassium description of similarity (1) e.g. soft metal/very reactive metal
2 allow 1 mark for description of similarity without named elements. NOT any reference to atomic structures / particles
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 1 d his predictions were accurate/proved to be
correct (1) he left gaps in the correct places for these elements to fit into his Periodic Table / newly discovered elements fitted into the gaps he left (1)
2 ignore references to predictions following a trend or based on properties of elements already discovered
e the same data can be interpreted in different ways / different parts of the data can be used (1) they were reluctant to say their ideas were wrong / reluctant to accept someone else’s idea were right (1)
2 ignore references to more data available now / better technology / hard to find a pattern that works / not all of the elements had been discovered not some ordered by atomic number allow new ideas are hard to accept
Total 13
29
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 2 a i keep warm / in range 20 – 40 oC (1)
pH neutral / pH 7.0 +/- 1.0 (1) QWC correct use of term temperature or pH or anaerobic (1)
3 allow anaerobic conditions / exclude air / exclude oxygen not heat
ii to increase ethanol concentration / to make pure ethanol
1 allow to separate ethanol from the reaction mixture
b i ethane to ethene (1) ethene reacted with steam (to make ethanol) (1) plus conditions used for either step i.e. by cracking / using heat / using catalyst for step 1 or by catalyst for step 2 (1)
ii ethane/crude oil/natural gas/fossil fuel will one day run out (1) fermentation uses plant material/source that can be grown (1)
2 not it will run out allow ethane is a non-renewable source / fermentation uses a renewable source without further details for one mark only ignore recycling / less pollution unqualified allow fermentation uses less energy (1) because it is at a lower temperature (1) / ora
30
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 2 c 3 all correct (3)
four correct (2) three or two correct (1) allow ethanol and oxygen in either order (on same line) allow carbon dioxide and water in either order (on same line)
Total 12
water carbon dioxide
energy released
oxygenethanol
31
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 3 a C2H4O2
/ CH3COOH
1 allow symbols for elements in any order Numbers must be subscript.
b i ethanoic acid + ethanol (ethyl ethanoate) + water
1 allow ethanoic acid and ethanol in either order
ii catalyst / speeds up reaction
1
iii any two from: in food in perfumes as solvents as plasticizers/make plastics flexible
2 any two allow examples of uses
c i reaction is reversible / reaction goes both forwards and backwards / reaction goes both ways
1 allow equilibrium reaction ignore reference to rate of reaction / concentrations
ii molecules (1) water (1) reverse (1) constant (1)
4
Total 10
32
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 4 a i
(D) C E A F (B)
3 all correct (3) or one mark per correct order: C before E (1) E before A (1) A before F (1)
ii to mix the contents
1
b i vinegar/ethanoic acid/acid
1
ii more accurate
1
ii conical flask / vinegar/ethanoic acid/acid
1
iv safety
1
c smaller range / closer together / less varied (1) more reliable / more consistent (1)
2 ignore precise ignore reference to outliers / correlation not more accurate not both more reliable and more accurate allow ora
Total 10
33
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 5 a it is made in large quantities
1 allow a lot is needed /manufactured more often
b rock is crushed (1) reacted with concentrated sulfuric acid (1) filtered (1) calcium sulfate dried and crushed into powder (1) concentrated acid is analysed (1)
5 allow the reaction
c i Beth
1
ii she identifies which chemicals other than phosphoric acid/impurities are present in the product
1 allow how pure the product is
d any two from: whether feedstock is renewable or not the atom economy disposal of the by-products/waste energy inputs / energy outputs environmental impact health and safety risks social and economic benefits
2 any two ignore specific references e.g. greenhouse gases / carbon dioxide
Total 10
34
A323/02 Mark Scheme June 2008
35
A323/02 Ideas in Context and Unit C7 - Higher
Question Expected Answers Marks Rationale
1 a they have the same number of / one electron(s) (1) in outer shell (1)
2 allow similar = same for number of electrons ignore need to lose one electron unless qualified allow missing one electron in outer shell = 1 allow incorrect number of electrons in outer shell = 1
b example of three elements in positions 8 places apart (1) e.g. lithium, sodium and potassium description of similarity (1) e.g. soft (metal) / very reactive (metal)
2 examples must be from first 20 elements 2nd mark depends on getting 1st mark ignore trend in group, e.g. reactivity increases / atomic number goes up in 8s not just gas for He Ne Ar but allow unreactive/inert gas
c his predictions were accurate/proved to be correct (1) he left gaps in the correct places for these elements to fit into his Periodic Table / newly discovered elements fitted into the gaps he left (1)
2 ignore references to predictions following a trend or based on properties of elements already discovered
d the same data can be interpreted in different ways / different parts of the data can be used (1) they were reluctant to say their ideas were wrong / reluctant to accept someone else’s idea were right (1)
2 ignore references to more data available now / better technology / hard to find a pattern that works / not all of the elements had been discovered not some ordered by atomic number allow new ideas are hard to accept
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
1 e i because he arranged them in order of RAM (1) the elements are in the wrong groups (1)
2 allow he swapped them round to reflect their properties ignore did not fit the pattern allow they are with elements with different properties
ii (in the modern Periodic Table) elements are in order of proton number/atomic number (not RAM)
1
f copper does not have similar properties to the other metals in Group 1 (1) example (1) : copper is unreactive unlike Group 1 metals / copper is less reactive / copper has higher mp / copper has coloured compounds / copper has variable valency
2 allow does not have one electron in outer shell allow ora
Total 13
36
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
2 a i C6H12O6 2C2H5OH + 2CO2
1 allow multiples
ii at lower temperature enzymes not active / at lower temperature reaction too slow (1) at higher temperature proteins destroyed / deactivated / denatured (1) QWC correct use of one term from collision frequency / active site / deactivated / denatured (1)
3 ignore references to optimum temperature allow reaction does not take place at low temperature allow reaction is slower at higher and lower temperatures = 1 allow yeast instead of protein not protein/enzyme/yeast killed
iii yeast killed by high concentration of ethanol 1 not kills enzymes allow ethanol is poisonous to yeast
b i RFMs C2H4 = 28 and C2H5OH = 46 (1) mass ethanol = 46/28 = 1.64 (1)
2 no ecf allow 1.64 = 2 marks allow 1.6 = 1 mark overall
ii ethane/crude oil/natural gas/fossil fuel will one day run out (1) fermentation uses plant material/source that can be grown (1)
2 not it will run out allow ethane is a non-renewable source / fermentation uses a renewable source without further details for one mark only ignore recycling / less pollution unqualified allow fermentation uses less energy (1) because it is at a lower temperature (1) / ora
37
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
2 c 3 all correct (3) four correct (2) three or two correct (1) allow ethanol and oxygen in either order (on same line) allow carbon dioxide and water in either order (on same line)
Total 12
ethanol oxygen
energy released
water carbon dioxide
38
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
3 a i reaction is reversible / reaction goes both forwards and backwards / reaction goes both ways
1 allow equilibrium reaction ignore reference to rate of reaction / concentrations
ii hydrochloric acid ionises completely (1) so hydrogen ion concentration is high (1) ethanoic acid only ionises partly / equilibrium is mainly to left / most of ethanoic acid is unionised (1) so hydrogen ion concentration is low (1)
4 allow there are more hydrogen ions in HCl than in ethanoic acid = 1 not strength of acid
b i CH3COOH + C2H5OH CH3COOC2H5 + H O 2
1
allow molecular formulas
ii 1 catalyst is not used up in the reaction
iii mixture heated in flask (1) with condenser above (1) so no liquid is lost by evaporation / allows onger time for the reaction (1) l
3 allow marks from diagram
Total 10
39
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
4 a i
(D) C E A F (B)
3 all correct (3) or one mark per correct order: C before E (1) E before A (1) A before F (1)
ii 4.0
1 allow 4
b i smaller range / closer together / less varied (1) more reliable / more consistent (1)
2 ignore precise ignore reference to outliers / correlation not more accurate not both more reliable and more accurate allow ora
ii mass = 4.0 x (60/40) x (12.5/25) (1) = 4.0 x 1.5 x 0.5 (1) = 3.0 (1) or mass NaOH in 12.5 cm3 = 4.0 x 12.5/1000 = 0.05 (allow 1.0 x 12.5/250 = 0.05) (1) mass acid in 25 cm3 = 0.005 x 60/40 =0.075 (1) mass in 1 dm3 = 0.075 x 1000/25 =3.0 (1)
3 allow any valid method allow any number in place of 4.0 as ecf allow correct answer alone (3 or 3.0) for full marks allow 0.075 = 2 marks
Total 9
40
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
5 a Ca3(PO4)2 + 3H2SO4 2H3PO4 + 3CaSO4 3 formulae on left (1) formulae on right (1) balanced (1)
b i waste will be acidic solution (1) may kill fish / kills vegetation / leaches phosphates / has to be removed/neutralised before it is released (1)
2 ignore vague answers such as ‘gets into water supply’, ‘harms the environment’ etc
ii to check for consistency (1) to make sure concentration is what is claimed on bottle (1)
2 ignore mention of impurities/purity allow check concentration is always the same/similar allow make sure it’s the strength you need / make sure it is safe to use ignore to find the yield
c any two from: make sure containers are strong (1) use sealed containers / make sure containers do not leak (1) make sure containers will not be corroded by acid (1) put warnings on containers (1) make drivers aware of hazards (1) put sign giving detail to fire service on back of tanker (1)
2 any two ignore use gloves, goggles etc
41
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
5 d any two from: whether feedstock is renewable or not (1) the atom economy (1) disposal of the by-products/waste (1) energy inputs / energy outputs (1) environmental impact (1) health and safety risks (1) social and economic benefits (1)
2 any two ignore specific references e.g. greenhouse gases / carbon dioxide
Total 11
42
43
Grade Thresholds
General Certificate of Secondary Education Chemistry A (Specification Code J634) June 2008 Examination Series Unit Threshold Marks
A329/A330 (Coursework) - The grade thresholds have been determined on the basis of the work that was presented for award in June 2008. The threshold marks will not necessarily be the same in subsequent awards. Specification Aggregation Results Overall threshold marks in UMS (ie after conversion of raw marks to uniform marks) Maximum
Mark A* A B C D E F G U
J634 300 270 240 210 180 150 120 90 60 0 The cumulative percentage of candidates awarded each grade was as follows:
A* A B C D E F G U Total No. of Cands
J634 17.6 50.1 80.8 95.0 98.6 99.6 99.9 100.0 100.0 10 392 11 008 candidates were entered for aggregation this series For a description of how UMS marks are calculated see: http://www.ocr.org.uk/learners/ums_results.html Statistics are correct at the time of publication.
OCR (Oxford Cambridge and RSA Examinations) 1 Hills Road Cambridge CB1 2EU OCR Customer Contact Centre 14 – 19 Qualifications (General) Telephone: 01223 553998 Facsimile: 01223 552627 Email: [email protected] www.ocr.org.uk For staff training purposes and as part of our quality assurance programme your call may be recorded or monitored
• Write your name in capital letters, your Centre Number and Candidate Number in the boxes above.• Use blue or black ink. Pencil may be used for graphs and diagrams only.• Read each question carefully and make sure that you know what you have to do before starting your
answer.• Answer all the questions.• Do not write in the bar codes.• Write your answer to each question in the space provided.
INFORMATION FOR CANDIDATES
• The number of marks for each question is given in brackets [ ] at the end of each question or part question.
• The total number of marks for this paper is 55.• The Periodic Table is printed on the back page.• Where you see this icon you will be awarded a mark for the
quality of written communication in your answer.
FOR EXAMINER’S USE
Qu. Max. Mark
1 13
2 12
3 10
4 9
5 11
TOTAL 55
GENERAL CERTIFICATE OF SECONDARY EDUCATION A323/02TWENTY FIRST CENTURY SCIENCE
CHEMISTRY AUnit 3 Ideas in Context plus C7 (Higher Tier)
FRIDAY 23 MAY 2008 Afternoon
Time: 60 minutes
Candidates answer on the question paper.Additional materials (enclosed):Insert
Calculators may be used.Additional materials: Pencil Ruler (cm/mm)
2 Manufacturers around the world are trying to find alternative fuels to petrol and diesel. This will stop drivers using up the world’s fossil fuels. One alternative fuel is bio-ethanol, made by the fermentation of wheat or beet sugar.
Bio-ethanol can be mixed with petrol. When burned, this produces less carbon dioxide and other pollutants. Bio-ethanol also provides more energy and is a renewable energy source.
(a) Fermentation of carbohydrates by yeast produces a solution that is distilled to produce bio-ethanol.
(i) Balance the equation for this fermentation reaction.
C6H12O6 …… C2H5OH + …… CO2 [1]
(ii) The process is carried out at an optimum temperature.
Explain why higher temperatures are not used and why lower temperatures are not used.
Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (OCR) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.
OCR is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
GCSE Twenty First Century Science – Chemistry A (J634)
MARK SCHEMES FOR THE UNITS
Unit/Content Page Guidance for Examiners 1
A321/01 Modules C1, C2, C3 Foundation Tier 2
A321/02 Modules C1, C2, C3 Higher Tier 10
A322/01 Modules C4, C5, C6 Foundation Tier 18
A322/02 Modules C4, C5, C6 Higher Tier 23
A323/01 Ideas in Context and Unit C7 - Foundation 28
A323/02 Ideas in Context and Unit C7 - Higher 35
Grade Thresholds 43
1
Guidance for Examiners 1. Mark strictly to the mark scheme.
2. Make no deductions for wrong work after an acceptable answer unless the mark scheme says otherwise.
3. Each separate marking point is indicated by a (1) at the end of that marking point.
4. Abbreviations, annotations and conventions used in the detailed Mark Scheme:
ORA = or reverse argument NOT = point that is not given credit AW/owtte = alternative wording/or words to that effect: allow any expression that is clearly equivalent / = Alternative and acceptable answers for the same marking point point = point must be present to gain the mark (description) = description which need not be present to gain the mark
E.g. mark scheme shows ‘work done in lifting / (change in) gravitational potential energy’ work done = 0 marks work done lifting = 1 mark change in potential energy = 0 marks gravitational potential energy = 1 mark
5. If a candidate alters his/her response, examiners should accept the alteration.
6. The list principle: if a list of responses greater than the number requested is given, you work through the list from the beginning. Award one mark for each correct response, ignore any neutral response, and deduct one mark for any incorrect response, i.e. one which has an error of science. If the number of incorrect responses is equal to or greater than the number of correct responses, no marks are awarded. A neutral response is correct but irrelevant to the question.
7. Marking method for tick boxes: If there is a set of boxes, some of which should be ticked and others left empty, then you
need to judge the entire set of boxes.
E.g. If a question requires candidates to identify a city in England, then in the boxes
Edinburgh Manchester Paris Southampton
the second and fourth boxes should have ticks (or other clear indication of choice) and the
first and third should be blank (or have indication of choice crossed out). For a two-mark question, the rationale would be:
All boxes are indicated scores 0 marks. All boxes blank scores 0 marks. All four boxes correct scores 2 marks. Three boxes correct scores 1 mark. Two boxes correct scores 1 mark. Edinburgh Manchester × Paris Southampton × Score: 2 2 1 1 1 1 0 0 0 NR
A321/01 Mark Scheme June 2008
2
A321/01 Modules C1, C2, C3 Foundation Tier
Question Expected Answers Marks Rationale
1 a
each bus carries many people
many people travelling to work in cars make more total pollutants
1
both required
b
pollutantproblem caused
sulfur dioxide
( ) ( )
nitrogen oxides
(1)
carbon (1)
2
both ticks per correct line (1) ignore tick in third box on first line (sulfur dioxide)
c
carbon monoxide (1)
1
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
d i Joe 1 more than one choice ringed = 0 marks
ii Eve and Liz 1 both required more than two choices ringed = 0 marks
Total 6
3
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
2 a
name of gas percentage
oxygen (21%)
nitrogen (78%) (1)
argon (>1%) (1)
(carbon dioxide) (0.03%)
2
oxygen and nitrogen in the right order (1) argon (1)
b i
CO2 has increased rapidly over the last 200 years
(1)
before 1800, there were small changes in CO2
(1)
2
ii
there are many more motor vehicles in the world
(1)
1
4
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
2 c i
1
one of the two oxygen molecules circled (1) allow both oxygen molecules circled not circle around one oxygen atom only not circle that includes other molecules
ii
(1)
1
d
dissolving in rainwater
dissolving in the sea
plant photosynthesis
2
all three correct (2) two correct (1)
e carbon dioxide (1) water (1)
2
Total 11
5
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
3 a i ramie 1 more than one choice ringed = 0 marks
ii sisal
1 more than one choice ringed = 0 marks
iii
Hemp ropes do not absorb water as much
(1)
It is easier to handle light ropes
(1)
2
b i
check reliability (1) calculate a best estimate (1)
2
ii 800 to 1500 1 both required in either order
iii some of the rope was damp (1) natural materials vary widely (1)
2
6
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
3 c
strong and waterproof (1)
1
Total 10
4 a i poly(ethene)
1 more than one choice ringed = 0 marks
ii bakelite and melamine
1 both required more than two choices ringed = 0 marks
b crude oil (1) hydrogen and carbon (1)
2 both hydrogen and carbon required, in either order
Total 4
5 land produces more food per acre (1) food is larger and free of pests (1)
2
Total 2
7
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
6 a 2
all three choices correct (2) one or two choices correct (1) more than one line from the same box on the left to different boxes on the right is an incorrect choice
b additives passed safety test (1) approved for use in the UK (1)
2
Total 4
colouring
preservative
emulsifier
mix ingredients
look attractive
prevent microbes
8
A321/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale
7 a
women with BMI of 25 are 5 times more likely to have type 2 diabetes than BMI 22
(1)
reducing your BMI may reduce your risk of getting type 2 diabetes
(1)
2
b true false
3
all correct (3) four correct (2) two or three correct (1)
Total 5
Paper Total 42
9
A321/02 Mark Scheme June 2008
10
Question Expected Answers Marks Rationale 1 a i X marked on graph above 310 ppm 1 an indication of this position anywhere on the graph on or
above the line of 310 ppm but not above 370 ppm = 1 mark ii
increase of about 100 ppm (1)
increase of about 30% (1)
2
per correct tick (1)
b i
(1)
1
A321/02 Modules C1, C2, C3 Higher Tier
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 1 ii
3 all correct (3) three correct (2) two or one correct (1) more than one line leaving a box on the left or approaching a box on the right loses that mark.
Total 7
11
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 2 a
each bus carries many people
many people travelling to work in cars make more total pollutants
1
both required
b
pollutant problem caused
sulfur dioxide
( ) ( )
nitrogen oxides
(1)
carbon (1)
2
both ticks per correct line (1) ignore tick in third box on first line (sulfur dioxide)
c
incomplete combustion of the fuel (1)
1
12
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 2 d
true false N.E.EEve Joe Liz Sab
3
all correct (3) three correct (2) one or two correct (1)
e true false
2
all correct (2) two or three correct (1)
Total 9
13
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 3 a i hemp and sisal 1
both required
ii
ranges for the values overlap (1)
1
iii
Hemp ropes do not absorb water as much
(1)
It is easier to handle light ropes
(1)
2
b i
check reliability (1) calculate a best estimate (1)
2
ii flax is a natural material
range is too wide for average
1
both required
14
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 3 c
advantage disadvantage
2
all four correct (2) two or three correct (1)
Total 9
4 a i poly(ethene)
1 more than one choice ringed = 0 marks
ii bakelite and melamine
1 both required more than two choices ringed = 0 marks
b
… is more flexible … has a lower tensile strength … polymer chains further apart
2
all correct (2) two correct (1)
Total 4
15
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 5 a
wheat roots take up nutrients (1)
ripe wheat is harvested (1)
2
b true
intensive true
organic true both
3
all correct (3) four correct (2) two or three correct (1)
Total 5
6
D
D
C
B
3
all correct (3) three correct (2) one or two correct (1)
Total 3
16
A321/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 7 a
women with BMI of 25 are 5 times more likely to have type 2 diabetes than BMI 22
(1)
reducing your BMI may reduce your risk of getting type 2 diabetes
(1)
2
b true false
3
all correct (3) four correct (2) two or three correct (1)
Total 5
Paper Total 42
17
A322/01 Mark Scheme June 2008
18
Question Expected Answers Marks Rationale 1 a Na (1)
K (1) 2 allow NA or na
b 3 per correctly joined right hand box (1) ensure that two lines are connected to the top right box; if one line is missing then lose one mark.
c i 3 six correctly joined pairs (3) five or four correctly joined pairs (2) three or two correctly joined pairs (1)
ii colourless 1
Total 9
black/purple
green
chlorine
bromine
solid
liquid
iodine gas orange/red
2.1
2.8.1
2.8.2
one electron in outer shell
two electrons in outer shell
three electrons in outer shell
2.8.3
A322/01 Modules C4, C5, C6 Foundation Tier
A322/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 2 a
elements compoundsoxygen carbon dioxide nitrogen water vapour
2 four rows correct (2) three or two rows correct (1) allow other clear identifying marks as well as ticks
b oxygen nitrogen carbon dioxide 1 all correct (1) allow incorrect spellings Allow symbols e.g. O/ O2 and N/N2 and CO2/CO2
Total 3
3 a
F
T
F
T
T
T
3 six correct (3) four or five correct (2) two or three correct (1) unmarked boxes are incorrect T or F must be clearly a T or an F rather than a combination or one overwritten on the other without clear decision. However, if the overwrite is clearly bolder, then allow.
b
bonds between particles are strong (1)
very large number of bonds (1)
2 if more than two boxes ticked then each extra box cancels a correct box
c Brenda (1) Daniel (1)
2 either order
Total 7
19
A322/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 4 a oxygen (1)
aluminium (1) 2 allow incorrect spellings
must be in this order not percentages
b compound 1
c sandstone 1
d mantle 1
Total 5
5 Carol (1) Delia (1)
2 either order
Total 2
6 impurities might have side effects (1) dose is the same every time (1) impossible to test new medicines (1)
3 per correct line (1) if more than three boxes ticked then each incorrect box cancels a correct box
Total 3
20
A322/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 7 a neutralisation
1
b 3 four correct lines (3) three or two correct lines (2) one correct line (1)
c reaction forms
a salt hydrogen gas water ( ) ( )
3 look at the question and all of the boxes as a whole. six correct boxes (3) five or four correct boxes (2) three or two correct boxes (1) one box correct scores zero
d sulfate (1) chloride (1)
2 allow sulphate, chloride/ chloride but no other incorrect spellings
e B 1 Allow H+ + OH-
21
A322/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 7 f
3 four correct lines (3)
three or two correct lines (2) one correct line (1)
Total 13
Paper Total 42
22
A322/02 Mark Scheme June 2008
23
A322/02 Modules C4, C5, C6 Higher Tier
Question Expected Answers Marks Rationale 1 Carol (1)
Delia (1)
2 either order
Total 2
2 a Brenda (1) Daniel (1)
2 either order
b MgCl21
c Li3N 1
d i
F
T
F
T
T
T
3 all correct (3) five or four correct (2) three or two correct (1) unmarked boxes are incorrect T or F must be clearly a T or an F rather than a combination or one overwritten on the other without clear decision. If overwrite is clearly bolder then allow.
ii bonds between particles are strong (1) very large number of bonds (1)
2 if more than two boxes ticked then each incorrect box cancels out a correct box
Total 9
A322/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 3 a
arrows 1 & 4 only (1)
1
b
arrow 1 only (1)
1
c i iodine and bromine (1) potassium and lithium (1) bromine (1)
3 allow any order allow any order
ii potassium and bromine 1 allow any order
24
A322/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 3 d
covalent ionic metallic
A
B
C
D
E
F
3 six rows correct (3) five or four correct (2) three or two correct (1) one correct (0) two ticks in one row = incorrect row
Total 9
4 B A C
2 three correct (2) two or one correct (1)
Total 2
5 impurities might have side effects (1) dose is the same every time (1) impossible to test new medicines (1)
3 per correct line (1) if more than three boxes ticked then each incorrect box cancels out a correct box
Total 3
25
A322/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 6 a Carl
1
b i 1g
1
ii 54g
1
Total 3
7 a B A F D E
2 all correct in correct order (2) C omitted from boxes, ABDEF in any order (1) Any answer that includes C scores 0
b i B
1
ii Al3+ + 3e- Al
1
iii arrow stays within the liquid and moves towards the right
1 If arrow goes to the left at any point then (0)
Total 5
26
A322/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale 8 a Denise 1
b 2 for correct start point (1) for correct end point (1) more than one line (0)
Total 3
9 a H2SO4 + 2 NaOH Na2SO4 + 2 H2O
2 per correct answer (1)
b B 1 Allow H+ + OH-
c
3 (1) for each fully correct line if more than three lines then each extra incorrect lines cancels out a correct line
Total 6
Paper Total 42
There is lots of acid and lots of alkali.
There is lots of acid and no alkali.A
There is no acid and lots of alkali.C
There is no acid and no alkali.E
There is some acid and some alkali.
27
A323/01 Mark Scheme June 2008
28
A323/01 Ideas in Context and Unit C7 - Foundation
Question Expected Answers Marks Rationale 1 a i lithium
sodium potassium / chlorine bromine iodine
2 all three names correct (2) two correct names (1) allow any order three correct symbols (1)
ii for alkali metals: they are soft metals they are very reactive metals/react with water They float (on water) for halogens: they are gases they are very reactive non-metals
2 answer must match triad chosen in (i)
b any three from: it contained several major flaws Newlands assumed all elements had been discovered two elements placed in the same position elements with different properties in same group
3 maximum three
c example of three elements in positions 8 places apart (1) e.g. lithium, sodium and potassium description of similarity (1) e.g. soft metal/very reactive metal
2 allow 1 mark for description of similarity without named elements. NOT any reference to atomic structures / particles
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 1 d his predictions were accurate/proved to be
correct (1) he left gaps in the correct places for these elements to fit into his Periodic Table / newly discovered elements fitted into the gaps he left (1)
2 ignore references to predictions following a trend or based on properties of elements already discovered
e the same data can be interpreted in different ways / different parts of the data can be used (1) they were reluctant to say their ideas were wrong / reluctant to accept someone else’s idea were right (1)
2 ignore references to more data available now / better technology / hard to find a pattern that works / not all of the elements had been discovered not some ordered by atomic number allow new ideas are hard to accept
Total 13
29
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 2 a i keep warm / in range 20 – 40 oC (1)
pH neutral / pH 7.0 +/- 1.0 (1) QWC correct use of term temperature or pH or anaerobic (1)
3 allow anaerobic conditions / exclude air / exclude oxygen not heat
ii to increase ethanol concentration / to make pure ethanol
1 allow to separate ethanol from the reaction mixture
b i ethane to ethene (1) ethene reacted with steam (to make ethanol) (1) plus conditions used for either step i.e. by cracking / using heat / using catalyst for step 1 or by catalyst for step 2 (1)
ii ethane/crude oil/natural gas/fossil fuel will one day run out (1) fermentation uses plant material/source that can be grown (1)
2 not it will run out allow ethane is a non-renewable source / fermentation uses a renewable source without further details for one mark only ignore recycling / less pollution unqualified allow fermentation uses less energy (1) because it is at a lower temperature (1) / ora
30
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 2 c 3 all correct (3)
four correct (2) three or two correct (1) allow ethanol and oxygen in either order (on same line) allow carbon dioxide and water in either order (on same line)
Total 12
water carbon dioxide
energy released
oxygenethanol
31
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 3 a C2H4O2
/ CH3COOH
1 allow symbols for elements in any order Numbers must be subscript.
b i ethanoic acid + ethanol (ethyl ethanoate) + water
1 allow ethanoic acid and ethanol in either order
ii catalyst / speeds up reaction
1
iii any two from: in food in perfumes as solvents as plasticizers/make plastics flexible
2 any two allow examples of uses
c i reaction is reversible / reaction goes both forwards and backwards / reaction goes both ways
1 allow equilibrium reaction ignore reference to rate of reaction / concentrations
ii molecules (1) water (1) reverse (1) constant (1)
4
Total 10
32
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 4 a i
(D) C E A F (B)
3 all correct (3) or one mark per correct order: C before E (1) E before A (1) A before F (1)
ii to mix the contents
1
b i vinegar/ethanoic acid/acid
1
ii more accurate
1
ii conical flask / vinegar/ethanoic acid/acid
1
iv safety
1
c smaller range / closer together / less varied (1) more reliable / more consistent (1)
2 ignore precise ignore reference to outliers / correlation not more accurate not both more reliable and more accurate allow ora
Total 10
33
A323/01 Mark Scheme June 2008
Question Expected Answers Marks Rationale 5 a it is made in large quantities
1 allow a lot is needed /manufactured more often
b rock is crushed (1) reacted with concentrated sulfuric acid (1) filtered (1) calcium sulfate dried and crushed into powder (1) concentrated acid is analysed (1)
5 allow the reaction
c i Beth
1
ii she identifies which chemicals other than phosphoric acid/impurities are present in the product
1 allow how pure the product is
d any two from: whether feedstock is renewable or not the atom economy disposal of the by-products/waste energy inputs / energy outputs environmental impact health and safety risks social and economic benefits
2 any two ignore specific references e.g. greenhouse gases / carbon dioxide
Total 10
34
A323/02 Mark Scheme June 2008
35
A323/02 Ideas in Context and Unit C7 - Higher
Question Expected Answers Marks Rationale
1 a they have the same number of / one electron(s) (1) in outer shell (1)
2 allow similar = same for number of electrons ignore need to lose one electron unless qualified allow missing one electron in outer shell = 1 allow incorrect number of electrons in outer shell = 1
b example of three elements in positions 8 places apart (1) e.g. lithium, sodium and potassium description of similarity (1) e.g. soft (metal) / very reactive (metal)
2 examples must be from first 20 elements 2nd mark depends on getting 1st mark ignore trend in group, e.g. reactivity increases / atomic number goes up in 8s not just gas for He Ne Ar but allow unreactive/inert gas
c his predictions were accurate/proved to be correct (1) he left gaps in the correct places for these elements to fit into his Periodic Table / newly discovered elements fitted into the gaps he left (1)
2 ignore references to predictions following a trend or based on properties of elements already discovered
d the same data can be interpreted in different ways / different parts of the data can be used (1) they were reluctant to say their ideas were wrong / reluctant to accept someone else’s idea were right (1)
2 ignore references to more data available now / better technology / hard to find a pattern that works / not all of the elements had been discovered not some ordered by atomic number allow new ideas are hard to accept
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
1 e i because he arranged them in order of RAM (1) the elements are in the wrong groups (1)
2 allow he swapped them round to reflect their properties ignore did not fit the pattern allow they are with elements with different properties
ii (in the modern Periodic Table) elements are in order of proton number/atomic number (not RAM)
1
f copper does not have similar properties to the other metals in Group 1 (1) example (1) : copper is unreactive unlike Group 1 metals / copper is less reactive / copper has higher mp / copper has coloured compounds / copper has variable valency
2 allow does not have one electron in outer shell allow ora
Total 13
36
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
2 a i C6H12O6 2C2H5OH + 2CO2
1 allow multiples
ii at lower temperature enzymes not active / at lower temperature reaction too slow (1) at higher temperature proteins destroyed / deactivated / denatured (1) QWC correct use of one term from collision frequency / active site / deactivated / denatured (1)
3 ignore references to optimum temperature allow reaction does not take place at low temperature allow reaction is slower at higher and lower temperatures = 1 allow yeast instead of protein not protein/enzyme/yeast killed
iii yeast killed by high concentration of ethanol 1 not kills enzymes allow ethanol is poisonous to yeast
b i RFMs C2H4 = 28 and C2H5OH = 46 (1) mass ethanol = 46/28 = 1.64 (1)
2 no ecf allow 1.64 = 2 marks allow 1.6 = 1 mark overall
ii ethane/crude oil/natural gas/fossil fuel will one day run out (1) fermentation uses plant material/source that can be grown (1)
2 not it will run out allow ethane is a non-renewable source / fermentation uses a renewable source without further details for one mark only ignore recycling / less pollution unqualified allow fermentation uses less energy (1) because it is at a lower temperature (1) / ora
37
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
2 c 3 all correct (3) four correct (2) three or two correct (1) allow ethanol and oxygen in either order (on same line) allow carbon dioxide and water in either order (on same line)
Total 12
ethanol oxygen
energy released
water carbon dioxide
38
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
3 a i reaction is reversible / reaction goes both forwards and backwards / reaction goes both ways
1 allow equilibrium reaction ignore reference to rate of reaction / concentrations
ii hydrochloric acid ionises completely (1) so hydrogen ion concentration is high (1) ethanoic acid only ionises partly / equilibrium is mainly to left / most of ethanoic acid is unionised (1) so hydrogen ion concentration is low (1)
4 allow there are more hydrogen ions in HCl than in ethanoic acid = 1 not strength of acid
b i CH3COOH + C2H5OH CH3COOC2H5 + H O 2
1
allow molecular formulas
ii 1 catalyst is not used up in the reaction
iii mixture heated in flask (1) with condenser above (1) so no liquid is lost by evaporation / allows onger time for the reaction (1) l
3 allow marks from diagram
Total 10
39
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
4 a i
(D) C E A F (B)
3 all correct (3) or one mark per correct order: C before E (1) E before A (1) A before F (1)
ii 4.0
1 allow 4
b i smaller range / closer together / less varied (1) more reliable / more consistent (1)
2 ignore precise ignore reference to outliers / correlation not more accurate not both more reliable and more accurate allow ora
ii mass = 4.0 x (60/40) x (12.5/25) (1) = 4.0 x 1.5 x 0.5 (1) = 3.0 (1) or mass NaOH in 12.5 cm3 = 4.0 x 12.5/1000 = 0.05 (allow 1.0 x 12.5/250 = 0.05) (1) mass acid in 25 cm3 = 0.005 x 60/40 =0.075 (1) mass in 1 dm3 = 0.075 x 1000/25 =3.0 (1)
3 allow any valid method allow any number in place of 4.0 as ecf allow correct answer alone (3 or 3.0) for full marks allow 0.075 = 2 marks
Total 9
40
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
5 a Ca3(PO4)2 + 3H2SO4 2H3PO4 + 3CaSO4 3 formulae on left (1) formulae on right (1) balanced (1)
b i waste will be acidic solution (1) may kill fish / kills vegetation / leaches phosphates / has to be removed/neutralised before it is released (1)
2 ignore vague answers such as ‘gets into water supply’, ‘harms the environment’ etc
ii to check for consistency (1) to make sure concentration is what is claimed on bottle (1)
2 ignore mention of impurities/purity allow check concentration is always the same/similar allow make sure it’s the strength you need / make sure it is safe to use ignore to find the yield
c any two from: make sure containers are strong (1) use sealed containers / make sure containers do not leak (1) make sure containers will not be corroded by acid (1) put warnings on containers (1) make drivers aware of hazards (1) put sign giving detail to fire service on back of tanker (1)
2 any two ignore use gloves, goggles etc
41
A323/02 Mark Scheme June 2008
Question Expected Answers Marks Rationale
5 d any two from: whether feedstock is renewable or not (1) the atom economy (1) disposal of the by-products/waste (1) energy inputs / energy outputs (1) environmental impact (1) health and safety risks (1) social and economic benefits (1)
2 any two ignore specific references e.g. greenhouse gases / carbon dioxide
Total 11
42
43
Grade Thresholds
General Certificate of Secondary Education Chemistry A (Specification Code J634) June 2008 Examination Series Unit Threshold Marks
A329/A330 (Coursework) - The grade thresholds have been determined on the basis of the work that was presented for award in June 2008. The threshold marks will not necessarily be the same in subsequent awards. Specification Aggregation Results Overall threshold marks in UMS (ie after conversion of raw marks to uniform marks) Maximum
Mark A* A B C D E F G U
J634 300 270 240 210 180 150 120 90 60 0 The cumulative percentage of candidates awarded each grade was as follows:
A* A B C D E F G U Total No. of Cands
J634 17.6 50.1 80.8 95.0 98.6 99.6 99.9 100.0 100.0 10 392 11 008 candidates were entered for aggregation this series For a description of how UMS marks are calculated see: http://www.ocr.org.uk/learners/ums_results.html Statistics are correct at the time of publication.
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