0654.C11.5.02 — Describe the test to distinguish between saturated and unsaturated hydrocarbons by their reaction with aqueous bromine: past paper questions
Real questions on 0654.c11.5.02 — describe the test to distinguish between saturated and unsaturated hydrocarbons by their reaction with aqueous bromine
The newest 14 of 14 written questions. Open one to see it on the real paper.
- 0973/42 · May/June 2026 · Q8a(iii)[1]
State the colour change, if any, when orange aqueous bromine is added to ethene to make product B.
See it on the paper → - 0973/31 · October/November 2025 · Q6a(iv)[1]
Aqueous bromine is used to distinguish between a saturated hydrocarbon and an unsaturated hydrocarbon. Describe the colour change that is observed when aqueous bromine is mixed with an unsaturated hydrocarbon.
See it on the paper → - 0973/41 · October/November 2025 · Q8b[1]
The diesel oil fraction can be cracked to make hydrocarbon molecules containing seven and eight carbon atoms. Tick (✓) one box. C 7 H 14 and C 8 H 18 C 7 H 14 and C 8 H 16 C 7 H 16 and C 8 H 16 State which pair of hydrocarbon molecules would both turn aqueous bromine colourless.
See it on the paper → - 0973/31 · October/November 2024 · Q11a(iv)[2]
State the chemical test for an unsaturated hydrocarbon. Give the observations for a positive result. test
See it on the paper → - 0973/42 · May/June 2024 · Q8a[2]
Ethene is an unsaturated hydrocarbon. Explain how the structure of ethene shows that ethene is an unsaturated hydrocarbon. unsaturated hydrocarbon
See it on the paper → - 0973/31 · October/November 2023 · Q5a(ii)[3]
Describe the chemical test that distinguishes between a saturated hydrocarbon and an unsaturated hydrocarbon and state the results for each. test result for a saturated hydrocarbon result for an unsaturated hydrocarbon
See it on the paper → - 0973/42 · May/June 2023 · Q2c[3]
Propane and propene are both colourless gases. Describe a test to show which gas is propane and which gas is propene. test result with propane result with propene
See it on the paper → - 0973/31 · October/November 2022 · Q5d(ii)[1]
An orange solution is used to test if a hydrocarbon molecule is unsaturated or saturated. State the name of this orange solution.
See it on the paper → - 0973/31 · October/November 2022 · Q5d(iii)[1]
Describe what is observed when the solution in (ii) is reacted with an unsaturated hydrocarbon molecule.
See it on the paper → - 0973/32 · May/June 2022 · Q11a(i)[1]
State which of the molecules P, Q, R or S is an alkene.
See it on the paper → - 0973/31 · October/November 2021 · Q8b(ii)[2]
Describe the chemical test and the positive result for an unsaturated hydrocarbon. test result
See it on the paper → - 0973/32 · May/June 2021 · Q11e(iii)[2]
State the chemical test for an unsaturated hydrocarbon and give the observation for a positive result. test
See it on the paper → - 0973/31 · October/November 2020 · Q5c(ii)[1]
Predict the change in colour, if any, when mixture Y is shaken with aqueous bromine.
See it on the paper → - 0973/31 · May/June 2020 · Q11c(i)[2]
Describe a test and its results that shows whether a compound is an alkane or an alkene. test result with an alkane result with an alkene
See it on the paper →
What examiners said
Many candidates could describe the use of aqueous bromine to differentiate between an alkane and an alkene. Very few confused the expected observations. Occasionally other incorrect tests were given, such as the use of limewater or flame tests. Very occasionally candidates were imprecise and described the result with propene as a clear colour rather than colourless.
— Examiner report, May/June 2023, 0973/42 Q2(c) (Cambridge)
The colour change from orange to colourless needs to be better known.
— Examiner report, October/November 2020, 0973/31 Q5(c)(ii) (Cambridge)
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