Skip to content
Try on iPad

Modern analytical techniques: OCR A‑Level Chemistry B questions

Every OCR A-Level Chemistry B exam question on WM Modern analytical techniques (specification points WM(i)–(j)), 2016–2025, with its mark scheme and examiner’s report.

Find questions2,049
Calculations

2,049 questions

  1. Q23(e)

    June 2025 · AS Paper 1

    1 markWM Modern analytical techniques
    The whole paper ↗
    June 2025 AS Paper 1, question 23(e): The mass spectrum of C6H12 has an (M+1)+ peak at 85. What causes this peak? [1]

  2. Q7

    June 2024 · Paper 1

    1 markWM Modern analytical techniques
    The whole paper ↗
    June 2024 Paper 1, question 7: In the mass spectrum of ethanoic acid (Mr = 60), what is the cause of the very small peak at m/z = 61? A the presence of an ethanol impurity in the ethanoic aci

  3. Q1(c)(iii)

    June 2024 · Paper 2

    1 markWM Modern analytical techniques
    The whole paper ↗
    June 2024 Paper 2, question 1(c)(iii): Mass spectrometry can be used to identify the emerging esters. Which property of the esters does mass spectrometry measure? [1]

  4. Q3(h)

    June 2024 · AS Paper 2

    6 marksWM Modern analytical techniquesEL Formulae, equations and amount of substance
    The whole paper ↗
    June 2024 AS Paper 2, question 3(h): Most diesel fuel is made from crude oil. However, biodiesel, made from vegetable oils, is increasingly being used. (h)* An organic compound A, has the following

  5. Q4(c)(ii)

    June 2023 · Paper 2

    3 marksWM Modern analytical techniques
    The whole paper ↗
    June 2023 Paper 2, question 4(c)(ii): Peaks are found at m / z values 15, 43 and 59 in the mass spectrum of propanone (Mr 58). Give the origin of these peaks. 15 43 59 [3]

  6. Q3(a)(i)

    June 2023 · Paper 3

    1 markWM Modern analytical techniques
    The whole paper ↗
    June 2023 Paper 3, question 3(a)(i): The IR spectrum of indigo has a significant absorption around 3300 cm–1. Suggest the most likely bond in indigo responsible for this absorption. [1]

  7. Q24(e)

    June 2023 · AS Paper 1

    4 marksWM Modern analytical techniques
    The whole paper ↗
    June 2023 AS Paper 1, question 24(e): The IR spectrum of a compound is shown below. 100 transmittance / % 50 0 4000 3000 2000 1500 1000 500 wavenumber / cm–1 The compound is one of: • ethanal • poly

  8. Q15

    June 2022 · Paper 1

    1 markWM Modern analytical techniques
    The whole paper ↗
    June 2022 Paper 1, question 15: What is the correct Mr value of the organic molecule whose mass spectrum is shown below? 100 80 60 Relative intensity 40 20 0 0 15 30 45 60 75 90 m / z A 75 B 7

  9. Q18

    June 2022 · AS Paper 1

    1 markWM Modern analytical techniques
    The whole paper ↗
    June 2022 AS Paper 1, question 18: The mass spectrum of (C3H7)2O has peaks at m/z 103, 102, 43 and other values. What is correct? A 102 is caused when the molecule gains an electron in the mass s

  10. Q3(a)(iii)

    June 2022 · AS Paper 2

    3 marksWM Modern analytical techniques
    The whole paper ↗
    June 2022 AS Paper 2, question 3(a)(iii): Reaction 1 occurs via the formation of compound C. CH2CHO Compound C The chemists use infrared spectroscopy to find out whether the conversion of compound A int

  11. Q3(a)

    November 2021 · Paper 2

    2 marksWM Modern analytical techniques
    The whole paper ↗
    November 2021 Paper 2, question 3(a): The mass spectrum of benzaldehyde has many peaks. Two of the peaks have m / z values of 107 and 77. Suggest explanations for these values. 107 77 [2]

  12. Q22(c)

    November 2021 · AS Paper 1

    2 marksWM Modern analytical techniques
    The whole paper ↗
    November 2021 AS Paper 1, question 22(c): The mass spectrum of phenol is shown below. 100 80 60 intensity / % 40 20 0 10 20 30 40 50 60 70 80 90 m / z Give the formula of the ion that causes the peak at

  13. Q22(d)

    November 2021 · AS Paper 1

    3 marksWM Modern analytical techniques
    The whole paper ↗
    November 2021 AS Paper 1, question 22(d): C6H5OH + (CH3CO)2O C6H5OCOCH3 + CH3COOH Equation 22.1 An infrared spectrum of one of the compounds in equation 22.1 is shown below. 100 50 transmittance / % 0 4

  14. Q21(b)(iii)

    November 2020 · AS Paper 1

    1 markWM Modern analytical techniques
    The whole paper ↗
    November 2020 AS Paper 1, question 21(b)(iii): Describe what happens to molecules when they absorb IR radiation. [1]

  15. Q22(b)(ii)

    November 2020 · AS Paper 1

    1 markWM Modern analytical techniques
    The whole paper ↗
    November 2020 AS Paper 1, question 22(b)(ii): A molecule consists of two carbon atoms. It has a visible ‘M+1’ peak but no visible ‘M+2’ peak in its mass spectrum. Suggest why. [1]

  16. Q22(c)

    November 2020 · AS Paper 1

    4 marksWM Modern analytical techniques
    The whole paper ↗
    November 2020 AS Paper 1, question 22(c): The mass spectrum of an alcohol is given below. The peak at 31 is caused by the fragment CH2OH+. 100 80 intensity / % 60 40 20 0 10 20 30 40 50 60 70 80 90 m /

  17. Q2(h)(i)

    June 2019 · Paper 3

    2 marksWM Modern analytical techniques
    The whole paper ↗
    June 2019 Paper 3, question 2(h)(i): Give the structures that produce the peaks at: 60 43 [2]

  18. Q2(h)(ii)

    June 2019 · Paper 3

    1 markWM Modern analytical techniques
    The whole paper ↗
    June 2019 Paper 3, question 2(h)(ii): Suggest why there is a small peak at 61. [1]

  19. Q7

    June 2019 · AS Paper 1

    1 markWM Modern analytical techniques
    The whole paper ↗
    June 2019 AS Paper 1, question 7: The mass spectrum of ethanoic acid has a peak at m/z 45. Which species could cause this? CH3COOH+ A COOH+ B 13CH3COOH+ C + D CH3 Your answer [1]

  20. Q1(g)(i)

    June 2019 · AS Paper 2

    1 markWM Modern analytical techniques
    The whole paper ↗
    June 2019 AS Paper 2, question 1(g)(i): Identify the biofuel given by the mass spectrum and infrared spectrum. [1]
All 30 questions on Modern analytical techniques, as a list
  1. June 2025, AS Paper 1, Q23(e) (1 mark): The mass spectrum of C6H12 has an (M+1)+ peak at 85. What causes this peak? [1]
  2. June 2024, Paper 1, Q7 (1 mark): In the mass spectrum of ethanoic acid (Mr = 60), what is the cause of the very small peak at m/z = 61? A the presence of an ethanol impurity in the ethanoic aci
  3. June 2024, Paper 2, Q1(c)(iii) (1 mark): Mass spectrometry can be used to identify the emerging esters. Which property of the esters does mass spectrometry measure? [1]
  4. June 2024, AS Paper 2, Q3(h) (6 marks): Most diesel fuel is made from crude oil. However, biodiesel, made from vegetable oils, is increasingly being used. (h)* An organic compound A, has the following
  5. June 2023, Paper 2, Q4(c)(ii) (3 marks): Peaks are found at m / z values 15, 43 and 59 in the mass spectrum of propanone (Mr 58). Give the origin of these peaks. 15 43 59 [3]
  6. June 2023, Paper 3, Q3(a)(i) (1 mark): The IR spectrum of indigo has a significant absorption around 3300 cm–1. Suggest the most likely bond in indigo responsible for this absorption. [1]
  7. June 2023, AS Paper 1, Q24(e) (4 marks): The IR spectrum of a compound is shown below. 100 transmittance / % 50 0 4000 3000 2000 1500 1000 500 wavenumber / cm–1 The compound is one of: • ethanal • poly
  8. June 2022, Paper 1, Q15 (1 mark): What is the correct Mr value of the organic molecule whose mass spectrum is shown below? 100 80 60 Relative intensity 40 20 0 0 15 30 45 60 75 90 m / z A 75 B 7
  9. June 2022, AS Paper 1, Q18 (1 mark): The mass spectrum of (C3H7)2O has peaks at m/z 103, 102, 43 and other values. What is correct? A 102 is caused when the molecule gains an electron in the mass s
  10. June 2022, AS Paper 2, Q3(a)(iii) (3 marks): Reaction 1 occurs via the formation of compound C. CH2CHO Compound C The chemists use infrared spectroscopy to find out whether the conversion of compound A int
  11. November 2021, Paper 2, Q3(a) (2 marks): The mass spectrum of benzaldehyde has many peaks. Two of the peaks have m / z values of 107 and 77. Suggest explanations for these values. 107 77 [2]
  12. November 2021, AS Paper 1, Q22(c) (2 marks): The mass spectrum of phenol is shown below. 100 80 60 intensity / % 40 20 0 10 20 30 40 50 60 70 80 90 m / z Give the formula of the ion that causes the peak at
  13. November 2021, AS Paper 1, Q22(d) (3 marks): C6H5OH + (CH3CO)2O C6H5OCOCH3 + CH3COOH Equation 22.1 An infrared spectrum of one of the compounds in equation 22.1 is shown below. 100 50 transmittance / % 0 4
  14. November 2020, AS Paper 1, Q21(b)(iii) (1 mark): Describe what happens to molecules when they absorb IR radiation. [1]
  15. November 2020, AS Paper 1, Q22(b)(ii) (1 mark): A molecule consists of two carbon atoms. It has a visible ‘M+1’ peak but no visible ‘M+2’ peak in its mass spectrum. Suggest why. [1]
  16. November 2020, AS Paper 1, Q22(c) (4 marks): The mass spectrum of an alcohol is given below. The peak at 31 is caused by the fragment CH2OH+. 100 80 intensity / % 60 40 20 0 10 20 30 40 50 60 70 80 90 m /
  17. June 2019, Paper 3, Q2(h)(i) (2 marks): Give the structures that produce the peaks at: 60 43 [2]
  18. June 2019, Paper 3, Q2(h)(ii) (1 mark): Suggest why there is a small peak at 61. [1]
  19. June 2019, AS Paper 1, Q7 (1 mark): The mass spectrum of ethanoic acid has a peak at m/z 45. Which species could cause this? CH3COOH+ A COOH+ B 13CH3COOH+ C + D CH3 Your answer [1]
  20. June 2019, AS Paper 2, Q1(g)(i) (1 mark): Identify the biofuel given by the mass spectrum and infrared spectrum. [1]
  21. June 2019, AS Paper 2, Q1(g)(ii) (1 mark): Give one piece of evidence from the mass spectrum to support your answer to (g)(i). [1]
  22. June 2019, AS Paper 2, Q1(g)(iii) (1 mark): Give one piece of evidence from the infrared spectrum to support your answer to (g)(i). [1]
  23. June 2018, Paper 2, Q2(a)(i) (2 marks): Give the species responsible for these peaks 27 43 [2]
  24. June 2018, AS Paper 2, Q2(g) (6 marks): Bioethanol is a well-known biofuel. Biobutanol is another biofuel and can be used in some combustion engines. Biobutanol can be produced in the UK from sugar be
  25. June 2017, Paper 1, Q18 (1 mark): What is correct about a mass spectrum of a compound? A It shows the atoms produced from the compound. B It enables the Mr of the compound to be determined. It h
  26. June 2017, Paper 3, Q3(e) (1 mark): Mass spectrometry can also be used to distinguish between ocimenol and cinnamyl alcohol. The molecular ion peak in a mass spectrum of ocimenol is at an m/z valu
  27. June 2017, AS Paper 1, Q21(c)(i) (1 mark): Give the formula of the ion responsible for the peak at m/z 64. [1]
  28. June 2017, AS Paper 1, Q21(c)(iii) (1 mark): Suggest the formula of the ion that gives the peak at m/z 65. [1]
  29. June 2017, AS Paper 1, Q21(d) (1 mark): Chloroethane can be converted to ethanol. The infrared spectrum of ethanol has some absorptions that are not present in the infrared spectrum of chloroethane. G
  30. June 2016, AS Paper 2, Q4(e) (6 marks): Ethanoic acid is an important chemical intermediate in the manufacture of a wide range of products. It was originally made by oxidising ethanol. (e)* An alcohol

Questions, mark schemes and examiner’s reports are © OCR, from their published past papers. Plumi isn’t affiliated with any exam board. Want whole papers? Every OCR A-Level Chemistry B paper.

Rather write your answers by hand on iPad? Plumi marks them against the same mark schemes.