Cambridge International AS & A Level
* 9 6 6 3 5 2 3 0 3 4 *
CHEMISTRY 9701/52
Paper 5 Planning, Analysis and Evaluation May/June 2023
1 hour 15 minutes
You must answer on the question paper.
No additional materials are needed.
INSTRUCTIONS
● Answer all questions.
● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs.
● Write your name, centre number and candidate number in the boxes at the top of the page.
● Write your answer to each question in the space provided.
● Do not use an erasable pen or correction fluid.
● Do not write on any bar codes.
● You may use a calculator.
● You should show all your working and use appropriate units.
INFORMATION
● The total mark for this paper is 30.
● The number of marks for each question or part question is shown in brackets [ ].
● The Periodic Table is printed in the question paper.
● Important values, constants and standards are printed in the question paper.
This document has 12 pages.
DC (LK/SG) 309547/6
© UCLES 2023 [Turn over
, 2
1 Three students are asked to prepare samples of benzoic acid, C6H5COOH, from the alkaline
hydrolysis of methyl benzoate, C6H5COOCH3. Sodium benzoate, C6H5COONa, is the salt formed,
which is then acidified with hydrochloric acid to form C6H5COOH.
C6H5COOCH3(l) + NaOH(aq) C6H5COONa(aq) + CH3OH(l)
C6H5COONa(aq) + HCl (aq) C6H5COOH(s) + NaCl (aq)
The students use the following method.
step 1 Put 1.242 g of liquid methyl benzoate into a 50 cm3 round-bottomed flask.
step 2 Prepare 100.0 cm3 of 1.00 mol dm–3 aqueous sodium hydroxide, NaOH(aq).
step 3 Add 10 cm3, an excess, of the prepared NaOH(aq) to the round-bottomed flask.
step 4 Add some anti-bumping granules to the round-bottomed flask.
step 5 Fit a condenser to make reflux apparatus. Reflux the reaction mixture for 20 minutes.
step 6 Allow the reaction mixture to cool and carefully pour the liquid into a beaker.
step 7 Acidify the liquid with dilute hydrochloric acid.
step 8 Filter the mixture formed in step 7.
step 9 Purify the benzoic acid by recrystallisation from hot water. Filter, dry and record the mass
of pure benzoic acid obtained.
(a) (i) Calculate the volume of methyl benzoate used in step 1.
Give your answer to the nearest 0.05 cm3.
[density: methyl benzoate, 1.08 g cm–3]
volume of methyl benzoate = .............................. cm3 [1]
(ii) Identify a suitable piece of apparatus to measure the volume of methyl benzoate required
in step 1.
..................................................................................................................................... [1]
(iii) Calculate the mass of NaOH(s) that is needed to prepare the solution in step 2.
mass of NaOH(s) = .............................. g [1]
© UCLES 2023 9701/52/M/J/23
, 3
(b) Student 1 added the mass of NaOH(s) calculated in (a)(iii) into a beaker.
Describe the steps the student should take to make 100.0 cm3 of 1.00 mol dm–3 NaOH(aq).
Give the name and capacity of any apparatus that should be used.
Write your answer using a series of numbered steps.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [3]
(c) Student 2 prepared 0.100 mol dm–3 NaOH(aq) instead of 1.00 mol dm–3 NaOH(aq) in step 2.
State how this would affect the final mass of benzoic acid formed. Explain, using calculations,
how you came to this conclusion.
[Mr : methyl benzoate, 136; benzoic acid, 122]
effect on mass ..........................................................................................................................
explanation
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
[2]
(d) (i) Explain why it is necessary to reflux the mixture in step 5.
...........................................................................................................................................
..................................................................................................................................... [1]
(ii) Explain why a naked flame is not used in step 5.
..................................................................................................................................... [1]
(iii) Explain the purpose of transferring the liquid in step 6.
..................................................................................................................................... [1]
© UCLES 2023 9701/52/M/J/23 [Turn over
* 9 6 6 3 5 2 3 0 3 4 *
CHEMISTRY 9701/52
Paper 5 Planning, Analysis and Evaluation May/June 2023
1 hour 15 minutes
You must answer on the question paper.
No additional materials are needed.
INSTRUCTIONS
● Answer all questions.
● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs.
● Write your name, centre number and candidate number in the boxes at the top of the page.
● Write your answer to each question in the space provided.
● Do not use an erasable pen or correction fluid.
● Do not write on any bar codes.
● You may use a calculator.
● You should show all your working and use appropriate units.
INFORMATION
● The total mark for this paper is 30.
● The number of marks for each question or part question is shown in brackets [ ].
● The Periodic Table is printed in the question paper.
● Important values, constants and standards are printed in the question paper.
This document has 12 pages.
DC (LK/SG) 309547/6
© UCLES 2023 [Turn over
, 2
1 Three students are asked to prepare samples of benzoic acid, C6H5COOH, from the alkaline
hydrolysis of methyl benzoate, C6H5COOCH3. Sodium benzoate, C6H5COONa, is the salt formed,
which is then acidified with hydrochloric acid to form C6H5COOH.
C6H5COOCH3(l) + NaOH(aq) C6H5COONa(aq) + CH3OH(l)
C6H5COONa(aq) + HCl (aq) C6H5COOH(s) + NaCl (aq)
The students use the following method.
step 1 Put 1.242 g of liquid methyl benzoate into a 50 cm3 round-bottomed flask.
step 2 Prepare 100.0 cm3 of 1.00 mol dm–3 aqueous sodium hydroxide, NaOH(aq).
step 3 Add 10 cm3, an excess, of the prepared NaOH(aq) to the round-bottomed flask.
step 4 Add some anti-bumping granules to the round-bottomed flask.
step 5 Fit a condenser to make reflux apparatus. Reflux the reaction mixture for 20 minutes.
step 6 Allow the reaction mixture to cool and carefully pour the liquid into a beaker.
step 7 Acidify the liquid with dilute hydrochloric acid.
step 8 Filter the mixture formed in step 7.
step 9 Purify the benzoic acid by recrystallisation from hot water. Filter, dry and record the mass
of pure benzoic acid obtained.
(a) (i) Calculate the volume of methyl benzoate used in step 1.
Give your answer to the nearest 0.05 cm3.
[density: methyl benzoate, 1.08 g cm–3]
volume of methyl benzoate = .............................. cm3 [1]
(ii) Identify a suitable piece of apparatus to measure the volume of methyl benzoate required
in step 1.
..................................................................................................................................... [1]
(iii) Calculate the mass of NaOH(s) that is needed to prepare the solution in step 2.
mass of NaOH(s) = .............................. g [1]
© UCLES 2023 9701/52/M/J/23
, 3
(b) Student 1 added the mass of NaOH(s) calculated in (a)(iii) into a beaker.
Describe the steps the student should take to make 100.0 cm3 of 1.00 mol dm–3 NaOH(aq).
Give the name and capacity of any apparatus that should be used.
Write your answer using a series of numbered steps.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [3]
(c) Student 2 prepared 0.100 mol dm–3 NaOH(aq) instead of 1.00 mol dm–3 NaOH(aq) in step 2.
State how this would affect the final mass of benzoic acid formed. Explain, using calculations,
how you came to this conclusion.
[Mr : methyl benzoate, 136; benzoic acid, 122]
effect on mass ..........................................................................................................................
explanation
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
[2]
(d) (i) Explain why it is necessary to reflux the mixture in step 5.
...........................................................................................................................................
..................................................................................................................................... [1]
(ii) Explain why a naked flame is not used in step 5.
..................................................................................................................................... [1]
(iii) Explain the purpose of transferring the liquid in step 6.
..................................................................................................................................... [1]
© UCLES 2023 9701/52/M/J/23 [Turn over
