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Organic synthesis: OCR A‑Level Chemistry A questions

Every OCR A-Level Chemistry A exam question on 4.2.3 Organic synthesis, 2016–2025, with its mark scheme and examiner’s report.

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1,820 questions

  1. Q4

    June 2025 · Paper 2

    1 mark4.2.3 Organic synthesis
    The whole paper ↗
    June 2025 Paper 2, question 4: Which diagram shows the correct way to set up apparatus for converting ethanol to ethanoic acid? water out water in A B water in water out water out water in wa

  2. Q17

    June 2025 · Paper 2

    6 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2025 Paper 2, question 17: 17* This question is about an organic synthesis. A student plans a two-stage synthesis of compound F from compound D, as shown below. Cl OH OH O Stage 1 Stage 2

  3. Q19(b)(ii)

    June 2025 · Paper 2

    4 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2025 Paper 2, question 19(b)(ii): The reaction to form 1-bromopropane from propan-1-ol is carried out in a flask. After the reaction, the flask contains a mixture of an organic layer (density =

  4. Q5(c)

    June 2025 · AS Paper 2

    6 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2025 AS Paper 2, question 5(c): This question is about haloalkanes. (c)* 2-Chlorobutane, CH3CH2CHCl CH3, is an organic liquid with a boiling point of 70 °C. A student prepares 2-chlorobutane f

  5. Q5(d)(i)

    June 2025 · AS Paper 2

    3 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2025 AS Paper 2, question 5(d)(i): Draw the structure of the hydrocarbon alkene X in the box and write down the reagents for each stage on the dotted lines. Alkene X Stage 1 Br Br H CH3 H H C C C

  6. Q23(a)

    June 2024 · Paper 2

    1 mark4.2.3 Organic synthesis
    The whole paper ↗
    June 2024 Paper 2, question 23(a): Why does the student use reflux in Step 1? [1]

  7. Q23(d)

    June 2024 · Paper 2

    4 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2024 Paper 2, question 23(d): Describe how to purify the impure compound H from the two layers in Step 2. [4]

  8. Q25(c)

    June 2024 · AS Paper 1

    2 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2024 AS Paper 1, question 25(c): Primary alcohols can be oxidised under distillation to make aldehydes. Draw a labelled diagram to show how you would set up apparatus for distillation. [2]

  9. Q5(b)(i)

    June 2023 · Paper 3

    2 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2023 Paper 3, question 5(b)(i): Draw a labelled diagram of suitable apparatus for reflux. [2]

  10. Q18

    June 2023 · AS Paper 1

    1 mark4.2.3 Organic synthesis
    The whole paper ↗
    June 2023 AS Paper 1, question 18: A student has planned the two-stage synthesis shown below. OH OH H3C H C C Intermediate H3C C C H H3C H CH3 H Which compound could be the intermediate for this

  11. Q3(a)

    June 2022 · Paper 3

    6 marks4.2.3 Organic synthesis2.1.3 Amount of substance
    The whole paper ↗
    June 2022 Paper 3, question 3(a): Information about 1-bromobutane and butan-1-ol is shown in the table. Density / g cm–3 Compound Melting point / °C Boiling point / °C 1-bromobutane –113 102 1.2

  12. Q5(c)(ii)

    June 2022 · AS Paper 2

    3 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2022 AS Paper 2, question 5(c)(ii): The student mixes butan-2-ol, sodium bromide and sulfuric acid in a pear-shaped flask, and refluxes the mixture. After 1 hour, the mixture in the flask has sepa

  13. Q24(c)(ii)

    November 2021 · AS Paper 1

    2 marks4.2.3 Organic synthesis
    The whole paper ↗
    November 2021 AS Paper 1, question 24(c)(ii): Draw a labelled diagram to show how you would set up apparatus for reflux. [2]

  14. Q7(b)

    November 2021 · AS Paper 2

    6 marks4.2.3 Organic synthesis
    The whole paper ↗
    November 2021 AS Paper 2, question 7(b): 2-Chloro-2-methylpropane, (CH3)3CCl , is an organic liquid with a boiling point of 50 °C. A student prepares (CH3)3CCl by reacting 2-methylpropan-2-ol, (CH3)3CO

  15. Q20(a)

    November 2020 · Paper 2

    6 marks4.2.3 Organic synthesis2.1.3 Amount of substance
    The whole paper ↗
    November 2020 Paper 2, question 20(a): Cyclopentanol can be reacted to form cyclopentene. Cyclopentene is a liquid with a boiling point of 44 °C and a density of 0.74 g cm−3. A student plans to prepa

  16. Q1(a)(i)

    November 2020 · Paper 3

    2 marks4.2.3 Organic synthesis
    The whole paper ↗
    November 2020 Paper 3, question 1(a)(i): Complete the missing labels on the diagram and name the technique. Heat Name of technique: [2]

  17. Q5(b)(i)

    June 2019 · AS Paper 2

    6 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2019 AS Paper 2, question 5(b)(i): Hex-1-ene is a liquid with a boiling point of 63 °C and a density of 0.67 g cm–3. Hex-1-ene can be prepared by refluxing hexan-1-ol (boiling point 157 °C) with

  18. Q19(c)(i)

    June 2018 · Paper 2

    2 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2018 Paper 2, question 19(c)(i): Draw a labelled diagram to show how the student would carry out the hydrolysis of haloalkane E. [2]

  19. Q5(a)(i)

    June 2018 · AS Paper 2

    6 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2018 AS Paper 2, question 5(a)(i): 1-Bromobutane is an organic liquid with a boiling point of 102 °C. A student prepares 1-bromobutane by reacting butan-1-ol with sulfuric acid and sodium bromide

  20. Q6(a)(i)

    June 2017 · AS Paper 2

    2 marks4.2.3 Organic synthesis
    The whole paper ↗
    June 2017 AS Paper 2, question 6(a)(i): Suggest the structure of intermediate E and the reagent(s) and conditions for step 2. reagent(s) and conditions [2]
All 22 questions on Organic synthesis, as a list
  1. June 2025, Paper 2, Q4 (1 mark): Which diagram shows the correct way to set up apparatus for converting ethanol to ethanoic acid? water out water in A B water in water out water out water in wa
  2. June 2025, Paper 2, Q17 (6 marks): 17* This question is about an organic synthesis. A student plans a two-stage synthesis of compound F from compound D, as shown below. Cl OH OH O Stage 1 Stage 2
  3. June 2025, Paper 2, Q19(b)(ii) (4 marks): The reaction to form 1-bromopropane from propan-1-ol is carried out in a flask. After the reaction, the flask contains a mixture of an organic layer (density =
  4. June 2025, AS Paper 2, Q5(c) (6 marks): This question is about haloalkanes. (c)* 2-Chlorobutane, CH3CH2CHCl CH3, is an organic liquid with a boiling point of 70 °C. A student prepares 2-chlorobutane f
  5. June 2025, AS Paper 2, Q5(d)(i) (3 marks): Draw the structure of the hydrocarbon alkene X in the box and write down the reagents for each stage on the dotted lines. Alkene X Stage 1 Br Br H CH3 H H C C C
  6. June 2024, Paper 2, Q23(a) (1 mark): Why does the student use reflux in Step 1? [1]
  7. June 2024, Paper 2, Q23(d) (4 marks): Describe how to purify the impure compound H from the two layers in Step 2. [4]
  8. June 2024, AS Paper 1, Q25(c) (2 marks): Primary alcohols can be oxidised under distillation to make aldehydes. Draw a labelled diagram to show how you would set up apparatus for distillation. [2]
  9. June 2023, Paper 3, Q5(b)(i) (2 marks): Draw a labelled diagram of suitable apparatus for reflux. [2]
  10. June 2023, AS Paper 1, Q18 (1 mark): A student has planned the two-stage synthesis shown below. OH OH H3C H C C Intermediate H3C C C H H3C H CH3 H Which compound could be the intermediate for this
  11. June 2022, Paper 3, Q3(a) (6 marks): Information about 1-bromobutane and butan-1-ol is shown in the table. Density / g cm–3 Compound Melting point / °C Boiling point / °C 1-bromobutane –113 102 1.2
  12. June 2022, AS Paper 2, Q5(c)(ii) (3 marks): The student mixes butan-2-ol, sodium bromide and sulfuric acid in a pear-shaped flask, and refluxes the mixture. After 1 hour, the mixture in the flask has sepa
  13. November 2021, AS Paper 1, Q24(c)(ii) (2 marks): Draw a labelled diagram to show how you would set up apparatus for reflux. [2]
  14. November 2021, AS Paper 2, Q7(b) (6 marks): 2-Chloro-2-methylpropane, (CH3)3CCl , is an organic liquid with a boiling point of 50 °C. A student prepares (CH3)3CCl by reacting 2-methylpropan-2-ol, (CH3)3CO
  15. November 2020, Paper 2, Q20(a) (6 marks): Cyclopentanol can be reacted to form cyclopentene. Cyclopentene is a liquid with a boiling point of 44 °C and a density of 0.74 g cm−3. A student plans to prepa
  16. November 2020, Paper 3, Q1(a)(i) (2 marks): Complete the missing labels on the diagram and name the technique. Heat Name of technique: [2]
  17. June 2019, AS Paper 2, Q5(b)(i) (6 marks): Hex-1-ene is a liquid with a boiling point of 63 °C and a density of 0.67 g cm–3. Hex-1-ene can be prepared by refluxing hexan-1-ol (boiling point 157 °C) with
  18. June 2018, Paper 2, Q19(c)(i) (2 marks): Draw a labelled diagram to show how the student would carry out the hydrolysis of haloalkane E. [2]
  19. June 2018, AS Paper 2, Q5(a)(i) (6 marks): 1-Bromobutane is an organic liquid with a boiling point of 102 °C. A student prepares 1-bromobutane by reacting butan-1-ol with sulfuric acid and sodium bromide
  20. June 2017, AS Paper 2, Q6(a)(i) (2 marks): Suggest the structure of intermediate E and the reagent(s) and conditions for step 2. reagent(s) and conditions [2]
  21. June 2016, AS Paper 1, Q26(c)(ii) (3 marks): A student plans a two-stage synthesis for preparing compound F from compound B. The synthesis first prepares compound E, as shown in the flowchart. Draw the str
  22. June 2016, AS Paper 2, Q6(c)(ii) (2 marks): A student plans to carry out this oxidation using the apparatus shown in the diagram. Give one reason why the apparatus is not suitable and describe a more suit

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