plumiOrganic Synthesis: Edexcel A‑Level Chemistry questions
Every Edexcel A-Level Chemistry exam question on 18C Organic Synthesis, 2016–2025, with its mark scheme and examiner’s report.
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Q6(a)
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Q9(b)(i)
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Q9(b)(ii)
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Q2(a)
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Q2(b)
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Q2(c)
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Q2(d)
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Q2(e)
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Q8(d)(ii)
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Q8(d)(iii)
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Q7(c)(i)
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Q7(c)(ii)
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Q7(c)(iii)
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Q7(d)(iii)
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Q7(c)(i)
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Q9(a)
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Q9(b)
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Q7(a)(ii)
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Q7(b)
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Q7(c)(i)
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All 51 questions on Organic Synthesis, as a list
- June 2025, Paper 3, Q6(a) (4 marks): A proposed synthesis of 2-methyl-1-phenylpropan-2-ol from phenylmethanol and propanone is shown. Complete the diagram to show the structures of compounds A, B a
- June 2025, Paper 3, Q9(b)(i) (3 marks): Explain how recrystallisation reduces the amount of soluble impurities. (3)
- June 2025, Paper 3, Q9(b)(ii) (2 marks): A student carrying out this procedure noticed some insoluble impurities in their sample. Describe how the procedure should be amended to remove these insoluble
- June 2024, Paper 2, Q2(a) (1 mark): The most suitable solvent for this reaction is (1) A cyclohexane B ether C ethyl ethanoate D hexane
- June 2024, Paper 2, Q2(b) (1 mark): State the use of Grignard reagents in organic synthesis. (1)
- June 2024, Paper 2, Q2(c) (1 mark): In their reactions, the Grignard reagent is best described as (1) A a carbocation B an electrophile C a nucleophile D a radical
- June 2024, Paper 2, Q2(d) (2 marks): Grignard reagents must be kept dry. Predict the organic product that forms when CH3CH2MgBr reacts with water. Justify your answer by considering the polarity of
- June 2024, Paper 2, Q2(e) (1 mark): Which compound will form a tertiary alcohol when it reacts with a Grignard reagent, followed by acid hydrolysis? (1) A CO2 B HCHO C CH3CHO D CH3COCH3
- June 2024, Paper 2, Q8(d)(ii) (2 marks): Name the two functional groups present in Compound Y. (2)
- June 2024, Paper 2, Q8(d)(iii) (2 marks): Give the reagent needed and conditions required for Step 3. (2)
- June 2024, Paper 3, Q7(c)(i) (1 mark): Name the solvent used. (1)
- June 2024, Paper 3, Q7(c)(ii) (2 marks): Explain why the anhydrous calcium chloride in Tube X is necessary. (2)
- June 2024, Paper 3, Q7(c)(iii) (1 mark): Give a reason why it is best practice for the water in the condenser to flow in the direction shown in the diagram. (1)
- June 2024, Paper 3, Q7(d)(iii) (4 marks): Describe how you would obtain pure dry crystals from the precipitate. (4)
- June 2023, Paper 2, Q7(c)(i) (3 marks): Identify the steps required to prepare a sample of a pure, dry derivative of a carbonyl compound X. (3) 2,4‑DNPH Carbonyl Precipitate in compound X reaction mix
- June 2023, Paper 2, Q9(a) (5 marks): A compound A (C3H7Cl) reacts with dilute aqueous sodium hydroxide to produce B (C3H8O). B can be oxidised to C (C3H6O), which cannot be oxidised any further. A
- June 2023, Paper 3, Q9(b) (7 marks): Four other C8H8O2 isomers were investigated. W and X are mono‑substituted aromatic compounds with the same functional • group as methyl benzoate but only W is m
- June 2022, Paper 3, Q7(a)(ii) (6 marks): Complete the table to show the information missing from the reaction scheme. (6) Reagent 2 Structure of compound A Reaction type 3 Structure of compound B Reage
- June 2022, Paper 3, Q7(b) (3 marks): Propanone can be formed from the fermentation of polysaccharides such as starch. The propanone can be separated from the fermentation mixture by distillation. D
- June 2022, Paper 3, Q7(c)(i) (2 marks): Explain why the filter paper and funnel are warmed in an oven before Step 3. (2)
- June 2022, Paper 3, Q7(c)(ii) (2 marks): Explain how Steps 4 and 5 remove impurities from the crystalline product. (2)
- November 2021, Paper 2, Q9(c)(i) (1 mark): The conversion of paracetamol to compound Z is (1) A addition B hydrolysis C oxidation D reduction
- November 2021, Paper 2, Q12 (6 marks): The alcohol 2,2-dimethylbutan-1-ol has the structure CH3 H2 H2 C C H3C C OH CH3 Devise a reaction scheme for a synthesis of this alcohol starting from 2-bromo-2
- November 2021, Paper 3, Q2(a) (2 marks): Deduce a chemical test which would give a positive result for A but not for B. Include the reagent and observation. (2)
- November 2021, Paper 3, Q6(c)(i) (3 marks): Draw a labelled diagram of the apparatus used for filtration under reduced pressure. (3)
- November 2021, Paper 3, Q6(c)(ii) (5 marks): Describe the recrystallisation process to obtain a pure, dry sample of paracetamol. (5)
- November 2021, Paper 3, Q6(c)(iii) (2 marks): The melting temperature of pure paracetamol is 170°C. Describe what happens to the melting temperature if the paracetamol is not pure. (2)
- October 2020, Paper 2, Q4(b) (6 marks): Compound T, C4H10O, is oxidised by acidified potassium dichromate(VI) to form compound U, C4H8O . U gives an orange precipitate with 2,4-dinitrophenylhydrazine
- October 2020, Paper 2, Q7(a)(i) (1 mark): LiAlH4 is a source of hydride ions, H−. Give a possible reason why LiAlH4 cannot be used to reduce alkenes. (1)
- October 2020, Paper 2, Q7(a)(iii) (1 mark): Step 2 is incorrect because alcohols can only be converted to nitriles via an intermediate compound. Identify a suitable intermediate compound by name or formu
- October 2020, Paper 2, Q7(b) (7 marks): Devise a four-step synthesis, involving the use of a Grignard reagent, to convert benzene into benzoyl chloride. O C Cl Include the reagents and conditions for
- October 2020, Paper 2, Q8(a)(iii) (1 mark): X has an unbranched carbon chain and does not exhibit geometric isomerism. Draw the skeletal formula of X. (1)
- October 2020, Paper 3, Q5(b) (1 mark): In Step 2 there is a pressure build-up in the separating funnel. Describe how you would lower the pressure. (1)
- October 2020, Paper 3, Q5(c) (1 mark): State why, in Step 4, the aqueous layer was the lower of the two layers. (1)
- October 2020, Paper 3, Q5(d) (1 mark): Give a reason why, in Step 5, the ether layer was washed with deionised water. (1)
- October 2020, Paper 3, Q5(f) (2 marks): Draw a diagram of the apparatus used in Step 7 to filter under reduced pressure. (2)
- October 2020, Paper 3, Q5(h) (2 marks): The melting temperature range of the purified benzoic acid in Step 9 was oC. 116–121 Compare this result with the literature value, giving a reason for any diff
- June 2019, Paper 2, Q8(a)(iii) (4 marks): Describe, in outline, how a sample of a solid, such as gentian violet, is purified by recrystallisation. Specific details of the solvent used are not required.
- June 2019, Paper 3, Q3(a) (5 marks): Propyl propanoate has the structure shown. H H O H H H H C C C O C C C H H H H H H Devise a synthetic pathway to prepare propyl propanoate starting with 1-bromo
- June 2019, Paper 3, Q3(b) (3 marks): Another ester, A, with molecular formula C6H12O2, was hydrolysed. It produced ethanoic acid, and an alcohol, B, with molecular formula C4H10O. Alcohol B undergo
- June 2019, Paper 3, Q9(c) (6 marks): Grignard reagents contain a metal. Discuss how Grignard reagents are formed and used in adding one or more carbon atoms to the carbon chain in 1-bromopropane to
- June 2019, Paper 3, Q10(a)(i) (3 marks): The masses of solids X and Y increased during the experiment. Explain the effect, if any, on the changes in mass of X and Y if the oxygen gas was not dry. (3)
- June 2018, Paper 2, Q7(a) (5 marks): Some of the following compounds can be used to make phenylethene from benzene. Aluminium chloride Chloroethane Ethanal Ethanol Ethanoic acid Ethanoyl chloride E
- June 2018, Paper 3, Q2(a) (7 marks): Lactic acid can be made in a two-step synthesis starting from ethanal, CH3CHO. Devise a reaction scheme for a two-step synthesis. Include in your answer all rea
- June 2018, Paper 3, Q6(e) (2 marks): The students could have identified the three structures using chemical tests. Complete the table to show whether or not the suggested structures react with brom
- June 2017, Paper 2, Q7(a) (5 marks): Some of the following reagents can be used to produce Antifebrin from benzene. • Aluminium chloride • Hydrochloric acid, dilute • Ammonia, concentrated • Iron •
- June 2017, Paper 3, Q5(a) (1 mark): The structure of the Grignard reagent formed by the reaction between 2-bromopropane and magnesium is CH3 H C MgBr CH3 On the diagram, draw the permanent dipole
- June 2017, Paper 3, Q5(b)(i) (1 mark): Draw the fully displayed formula of the final organic product of this reaction. (1)
- June 2017, Paper 3, Q5(b)(ii) (1 mark): Name the organic product in (b)(i). (1)
- June 2017, Paper 3, Q5(c) (2 marks): Identify, by using ticks, two boxes in the table to select appropriate terms that describe a Grignard reagent. (2) acid electrophile nucleophile oxidising agent
- June 2017, Paper 3, Q5(d) (1 mark): The solvent used for Grignard reagents has to be completely dry. By considering the dipole on the O—H bonds in water, predict the identity of the organic produc
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