Alkenes: past paper questions
Real questions on alkenes
The newest 20 of 61 written questions. Open one to see it on the real paper.
- 0971/42 · May/June 2026 · Q1b(i)[1]
is used to detect unsaturated hydrocarbon molecules
See it on the paper → - 0971/42 · May/June 2026 · Q1b(ii)[1]
gives a lilac flame test
See it on the paper → - 0971/32 · October/November 2025 · Q4b[1]
On Fig. 4.1, draw a circle around one part of the molecule responsible for the decolourisation of aqueous bromine.
See it on the paper → - 0971/32 · October/November 2025 · Q4f(i)[1]
Identify the unsaturated hydrocarbon in Table 4.2.
See it on the paper → - 0971/32 · October/November 2025 · Q4f(ii)[1]
Explain your answer in (f)(i).
See it on the paper → - 0971/31 · May/June 2025 · Q4e(ii)[1]
Explain why the molecule in Fig. 4.1 is unsaturated.
See it on the paper → - 0971/41 · May/June 2025 · Q1j[1]
is a monomer in addition polymerisation.
See it on the paper → - 0971/32 · October/November 2024 · Q4d(i)[1]
Name the homologous series that includes ethene, propene, butene and pentene.
See it on the paper → - 0971/32 · October/November 2024 · Q4d(ii)[1]
Deduce the general formula of this homologous series.
See it on the paper → - 0971/32 · October/November 2024 · Q4d(iii)[1]
State the trend in the boiling point of this homologous series as the number of carbon atoms increases.
See it on the paper → - 0971/42 · October/November 2024 · Q1g[1]
is unsaturated
See it on the paper → - 0971/31 · May/June 2024 · Q8c[2]
Describe how alkenes are manufactured from petroleum fractions. [Total: 9]
See it on the paper → - 0971/32 · May/June 2024 · Q4a(i)[1]
Draw the displayed formula for a molecule of ethene.
See it on the paper → - 0971/41 · May/June 2024 · Q1f[1]
manufacture alkenes and hydrogen from large alkane molecules
See it on the paper → - 0971/42 · May/June 2024 · Q1a(iii)[1]
is unsaturated
See it on the paper → - 0971/42 · May/June 2024 · Q6c(ii)[1]
Explain why this reaction is an addition reaction.
See it on the paper → - 0971/32 · October/November 2023 · Q1a[1]
is an unsaturated hydrocarbon
See it on the paper → - 0971/32 · October/November 2023 · Q7a(iii)[2]
Fumaric acid is a colourless compound. Describe the colour change when excess fumaric acid is added to aqueous bromine. from to ������������������������������������������������������������
See it on the paper → - 0971/31 · May/June 2023 · Q7a(iii)[2]
Mesaconic acid is a colourless compound. Describe the colour change when excess mesaconic acid is added to aqueous bromine. from to �������������������������������������������������������������
See it on the paper → - 0971/32 · May/June 2023 · Q7a(iii)[1]
Explain, by referring to the structure in Fig. 7.1, why compound D is unsaturated.
See it on the paper →
What examiners said
Many correctly identified unsaturation as the presence of the carbon-to-carbon double bond, C=C. A common error was to state ‘double bond’ without reference to the two carbon atoms. The molecule shown contains a C=O bond which, on its own, would not qualify the molecule as unsaturated
— Examiner report, May/June 2025, 0971/31 Q4(e)(ii) (Cambridge)
Many candidates identified the correct colours but reversed the order.
— Examiner report, May/June 2023, 0971/31 Q7(a)(iii) (Cambridge)
Many responses were too vague. It was important that a candidate referred to carbon–carbon bonds in their answer. An answer such as, ‘here is a carbon double bond’ is insufficient as the double bond could be to another atom such as oxygen in carboxylic acids.
— Examiner report, May/June 2023, 0971/42 Q5(b)(i) (Cambridge)
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