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Organic reactions: OCR A‑Level Chemistry B questions

Every OCR A-Level Chemistry B exam question on CD Organic reactions (specification points CD(g)–(j)), 2016–2025, with its mark scheme and examiner’s report.

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2,049 questions

  1. Q2(b)(iii)

    June 2025 · Paper 3

    1 markCD Organic reactions
    The whole paper ↗
    June 2025 Paper 3, question 2(b)(iii): Suggest a type of useful compound that can be made using compound X. [1]

  2. Q19

    June 2024 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    June 2024 Paper 1, question 19: What is correct about propanal, CH3CH2CHO, and propanone, CH3COCH3? A Only propanal can be oxidised by acidified dichromate. B Only propanal forms a ‘silver mir

  3. Q35(a)(i)

    June 2024 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    June 2024 Paper 1, question 35(a)(i): Name compound C. [1]

  4. Q35(a)(ii)

    June 2024 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    June 2024 Paper 1, question 35(a)(ii): Reaction 1 is an electrophilic substitution using concentrated sulfuric acid. Give the formula of the electrophile. [1]

  5. Q35(b)

    June 2024 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    June 2024 Paper 1, question 35(b): Use the Data Sheet to give reagents and conditions for reaction 3. [1]

  6. Q35(c)

    June 2024 · Paper 1

    3 marksCD Organic reactions
    The whole paper ↗
    June 2024 Paper 1, question 35(c): Reaction 4 forms a diazonium salt. Give the reagents and conditions for this reaction. Reagents: Conditions: [3]

  7. Q35(d)

    June 2024 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    June 2024 Paper 1, question 35(d): Reaction 5 is a coupling reaction, using a phenol and sodium hydroxide. Give the formula of the phenol. [1]

  8. Q29

    June 2023 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    June 2023 Paper 1, question 29: Which statement(s) is/are correct for a Friedel-Crafts alkylation reaction? 1 An alkyl group bonds with a benzene ring by an addition reaction. 2 Al Cl 3 is use

  9. Q4(f)

    June 2023 · Paper 2

    2 marksCD Organic reactions
    The whole paper ↗
    June 2023 Paper 2, question 4(f): Propan-1-ol is oxidised to an aldehyde rather than a ketone. Describe a laboratory test, and its result, that would distinguish this aldehyde from propanone. [2

  10. Q4(g)(ii)

    June 2023 · Paper 2

    1 markCD Organic reactions
    The whole paper ↗
    June 2023 Paper 2, question 4(g)(ii): Name the functional group formed in the product from (i). [1]

  11. Q3(d)(i)

    June 2023 · Paper 3

    4 marksCD Organic reactions
    The whole paper ↗
    June 2023 Paper 3, question 3(d)(i): The dye direct blue 15 does not fade, whereas indigo does. NH2 H2N OH HO NaO3S SO3Na N N N N SO3Na NaO3S CH3O OCH3 Direct blue 15 This dye is made by sulfonatio

  12. Q3(d)(ii)

    June 2023 · Paper 3

    2 marksCD Organic reactions
    The whole paper ↗
    June 2023 Paper 3, question 3(d)(ii): Dibromoindigo can be prepared synthetically by reacting indigo with bromine, using an iron catalyst. O H Br N N Br H O Dibromoindigo The reaction has the same t

  13. Q25

    June 2022 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    June 2022 Paper 1, question 25: The formation of an azo dye is shown in Reaction 25.1 below. + N2 Cl NH –2H+ O O + 2 O Cl N N H O N N O Cl Reaction 25.1 N + N2 Cl O HN Compound X Compound Y Co

  14. Q35(c)(i)

    June 2022 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    June 2022 Paper 1, question 35(c)(i): Explain why this reaction must be carried out in anhydrous conditions. [1]

  15. Q35(c)(ii)

    June 2022 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    June 2022 Paper 1, question 35(c)(ii): Name the mechanism of the reaction involved in this first step. [1]

  16. Q35(e)(ii)

    June 2022 · Paper 1

    2 marksCD Organic reactions
    The whole paper ↗
    June 2022 Paper 1, question 35(e)(ii): The conversion in Step 1 occurs through the intermediate formation of benzaldehyde. CHO benzaldehyde Describe a test-tube reaction that a student could carry ou

  17. Q35(e)(iv)

    June 2022 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    June 2022 Paper 1, question 35(e)(iv): In Step 2, the benzoic acid is reacted with a nitrating mixture of concentrated nitric and concentrated sulfuric acids. Write an equation to show the formation

  18. Q34(e)(i)

    November 2021 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    November 2021 Paper 1, question 34(e)(i): Use your Data Sheet to suggest a possible reagent for Reaction 3. [1]

  19. Q3(e)(ii)

    November 2021 · Paper 2

    1 markCD Organic reactions
    The whole paper ↗
    November 2021 Paper 2, question 3(e)(ii): Name the functional group attached to the benzene ring in compound C. [1]

  20. Q29

    November 2020 · Paper 1

    1 markCD Organic reactions
    The whole paper ↗
    November 2020 Paper 1, question 29: Which compound(s) can be made from benzene in one step? 1 C6H5Cl 2 C6H5NO2 3 C6H5NH2 A 1, 2 and 3 B Only 1 and 2 C Only 2 and 3 D Only 1 Your answer [1]
All 30 questions on Organic reactions, as a list
  1. June 2025, Paper 3, Q2(b)(iii) (1 mark): Suggest a type of useful compound that can be made using compound X. [1]
  2. June 2024, Paper 1, Q19 (1 mark): What is correct about propanal, CH3CH2CHO, and propanone, CH3COCH3? A Only propanal can be oxidised by acidified dichromate. B Only propanal forms a ‘silver mir
  3. June 2024, Paper 1, Q35(a)(i) (1 mark): Name compound C. [1]
  4. June 2024, Paper 1, Q35(a)(ii) (1 mark): Reaction 1 is an electrophilic substitution using concentrated sulfuric acid. Give the formula of the electrophile. [1]
  5. June 2024, Paper 1, Q35(b) (1 mark): Use the Data Sheet to give reagents and conditions for reaction 3. [1]
  6. June 2024, Paper 1, Q35(c) (3 marks): Reaction 4 forms a diazonium salt. Give the reagents and conditions for this reaction. Reagents: Conditions: [3]
  7. June 2024, Paper 1, Q35(d) (1 mark): Reaction 5 is a coupling reaction, using a phenol and sodium hydroxide. Give the formula of the phenol. [1]
  8. June 2023, Paper 1, Q29 (1 mark): Which statement(s) is/are correct for a Friedel-Crafts alkylation reaction? 1 An alkyl group bonds with a benzene ring by an addition reaction. 2 Al Cl 3 is use
  9. June 2023, Paper 2, Q4(f) (2 marks): Propan-1-ol is oxidised to an aldehyde rather than a ketone. Describe a laboratory test, and its result, that would distinguish this aldehyde from propanone. [2
  10. June 2023, Paper 2, Q4(g)(ii) (1 mark): Name the functional group formed in the product from (i). [1]
  11. June 2023, Paper 3, Q3(d)(i) (4 marks): The dye direct blue 15 does not fade, whereas indigo does. NH2 H2N OH HO NaO3S SO3Na N N N N SO3Na NaO3S CH3O OCH3 Direct blue 15 This dye is made by sulfonatio
  12. June 2023, Paper 3, Q3(d)(ii) (2 marks): Dibromoindigo can be prepared synthetically by reacting indigo with bromine, using an iron catalyst. O H Br N N Br H O Dibromoindigo The reaction has the same t
  13. June 2022, Paper 1, Q25 (1 mark): The formation of an azo dye is shown in Reaction 25.1 below. + N2 Cl NH –2H+ O O + 2 O Cl N N H O N N O Cl Reaction 25.1 N + N2 Cl O HN Compound X Compound Y Co
  14. June 2022, Paper 1, Q35(c)(i) (1 mark): Explain why this reaction must be carried out in anhydrous conditions. [1]
  15. June 2022, Paper 1, Q35(c)(ii) (1 mark): Name the mechanism of the reaction involved in this first step. [1]
  16. June 2022, Paper 1, Q35(e)(ii) (2 marks): The conversion in Step 1 occurs through the intermediate formation of benzaldehyde. CHO benzaldehyde Describe a test-tube reaction that a student could carry ou
  17. June 2022, Paper 1, Q35(e)(iv) (1 mark): In Step 2, the benzoic acid is reacted with a nitrating mixture of concentrated nitric and concentrated sulfuric acids. Write an equation to show the formation
  18. November 2021, Paper 1, Q34(e)(i) (1 mark): Use your Data Sheet to suggest a possible reagent for Reaction 3. [1]
  19. November 2021, Paper 2, Q3(e)(ii) (1 mark): Name the functional group attached to the benzene ring in compound C. [1]
  20. November 2020, Paper 1, Q29 (1 mark): Which compound(s) can be made from benzene in one step? 1 C6H5Cl 2 C6H5NO2 3 C6H5NH2 A 1, 2 and 3 B Only 1 and 2 C Only 2 and 3 D Only 1 Your answer [1]
  21. November 2020, Paper 1, Q34(a) (3 marks): The students synthesise dye C, shown below, in two steps. Complete the reaction sequence by filling in the boxes. NH2 Reagents for step 1: NaNO2 + HCl Condition
  22. November 2020, Paper 1, Q34(b)(i) (1 mark): Suggest a reagent and the conditions that would turn dye C into dye D. [1]
  23. June 2019, Paper 1, Q33(f)(ii) (1 mark): Give the equation for the reaction of HCN with the functional group identified in (f)(i). [1]
  24. June 2019, Paper 1, Q35(d)(i) (3 marks): Fill in the table to show the reagents, conditions and colour changes for their tests. Reagent(s) Conditions Colour change Oxidation of alcohol Identification o
  25. June 2019, Paper 2, Q1(d) (2 marks): A synthetic route for making compound B is shown in Fig. 1.3. Cl NO2 H2N NO2 H2N NH2 step 1 step 2 compound B Fig. 1.3 Use your chemical knowledge and the Data
  26. June 2018, Paper 3, Q1(a) (3 marks): The student initially makes a small amount of a solution of the diazonium compound shown below, starting from an aromatic amine. + N Cl – N diazonium compound N
  27. June 2018, Paper 3, Q1(b)(i) (1 mark): Complete the structure of the azo dye formed in this coupling reaction. OH [1]
  28. June 2017, Paper 1, Q34(b)(i) (2 marks): This is an electrophilic substitution reaction. Give the conditions for the reaction and an equation to show how the electrophile is formed. Conditions Equation
  29. June 2017, Paper 1, Q34(b)(ii) (4 marks): The nitrobenzene is then changed to phenylamine. The flow diagram shows how the student could produce the red dye shown from phenylamine. Complete the diagram b
  30. June 2017, Paper 2, Q3(a)(iii) (2 marks): Describe a laboratory test for the functional group identified in (a)(ii). [2]

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