Alkenes: past paper questions
Real questions on alkenes
The newest 20 of 98 written questions. Open one to see it on the real paper.
- 0620/31 · May/June 2026 · Q1b(i)[2]
State which two substances are hydrocarbons. and
See it on the paper → - 0620/31 · May/June 2026 · Q7d(i)[1]
Name the three elements present in an NPK fertiliser.
See it on the paper → - 0620/31 · May/June 2026 · Q7d(ii)[1]
Explain why fertilisers are used.
See it on the paper → - 0620/33 · May/June 2026 · Q1a(i)[1]
is an alkene
See it on the paper → - 0620/33 · May/June 2026 · Q1a(vi)[1]
is in a homologous series with the general formula C n H 2n .
See it on the paper → - 0620/33 · May/June 2026 · Q4c[3]
Outline how ethanol is manufactured from ethene and steam. In your answer, include: • • the name of this reaction two conditions that are needed. name of reaction condition
See it on the paper → - 0620/41 · May/June 2026 · Q7c(i)[1]
Give the empirical formula of all alkenes.
See it on the paper → - 0620/41 · May/June 2026 · Q7c(ii)[2]
Name two unbranched alkene molecules that each contain four carbon atoms.
See it on the paper → - 0620/42 · May/June 2026 · Q1b(i)[1]
is used to detect unsaturated hydrocarbon molecules
See it on the paper → - 0620/42 · May/June 2026 · Q1b(ii)[1]
gives a lilac flame test
See it on the paper → - 0620/32 · February/March 2026 · Q2b(iii)[2]
A test-tube contains aqueous bromine. Describe the colour change when excess compound P is added to the test-tube. from to (iii)
See it on the paper → - 0620/31 · October/November 2025 · Q4g(ii)[2]
Ethene is one of the molecules formed when decane is heated strongly in the presence of a catalyst. Draw the displayed formula of ethene. Show all the atoms and all the bonds.
See it on the paper → - 0620/32 · 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 → - 0620/32 · October/November 2025 · Q4f(i)[1]
Identify the unsaturated hydrocarbon in Table 4.2.
See it on the paper → - 0620/32 · October/November 2025 · Q4f(ii)[1]
Explain your answer in (f)(i).
See it on the paper → - 0620/33 · October/November 2025 · Q4b[1]
On Fig. 4.1, draw a circle around one part of the molecule which shows that the molecule is unsaturated.
See it on the paper → - 0620/33 · May/June 2025 · Q3e(ii)[1]
Explain why the molecule in Fig. 3.1 is unsaturated.
See it on the paper → - 0620/41 · May/June 2025 · Q1j[1]
is a monomer in addition polymerisation.
See it on the paper → - 0620/43 · May/June 2025 · Q1b[1]
is an unsaturated hydrocarbon
See it on the paper → - 0620/43 · May/June 2025 · Q1e[1]
contains simple molecules with 9 atoms
See it on the paper →
What examiners said
Comprehensive responses • Most candidates knew at least one of the colours for this chemical test. Limited responses • Some candidates got confused with the correct colour change and put the colours the other way around. • A few candidates used colour changes that were for different reactions.
— Examiner report, February/March 2026, 0620/32 Q2(b)(iii) (Cambridge)
Candidates needed to be more specific in answering this question. Many candidates gave ‘double bond’ in their answer but then omitted to mention that it was a carbon carbon double bond. Some candidates misinterpreted this question and thought that the question was asking about the meaning of the term ‘unsaturated solution’.
— Examiner report, May/June 2025, 0620/33 Q3(e)(ii) (Cambridge)
Propane was the most common incorrect answer, with candidates either unclear on the meaning of unsaturated or confusing alkanes with alkenes. Ethanol was also a common incorrect answer, with many not realising that it is not a hydrocarbon.
— Examiner report, May/June 2025, 0620/43 Q1(b) (Cambridge)
Past papers, syllabus and examiner reports © UCLES (Cambridge University Press & Assessment). Questions are matched to topics from the official syllabus. AssessPro is independent and not endorsed by Cambridge.