The newest 10 of 10 written questions. Open one to see it on the real paper.
Butene, C 4 H 8 , reacts with bromine. State what would be observed in the reaction.
See it on the paper →The equation for the reaction is C 4 H 8 + Br 2 C 4 H 8 Br 2 State what type of reaction this is. addition combustion cracking polymerisation answer Choose your answer from the list.
See it on the paper →State which compound reacts with bromine to form C 2 H 4 Br 2 . Choose from A, B, C, D or E.
See it on the paper →Describe a chemical test that distinguishes between an alkane and an alkene. Describe the observations for a positive result of the test in each case. test for an alkane for an alkene
See it on the paper →Propene can be changed into propane by reaction with hydrogen, as shown in Fig. 5.2. H H C H C C H H H + H 2 H H H H C C C H H H H Fig. 5.2 State the name of this type of reaction.
See it on the paper →Name the process that produces smaller unsaturated hydrocarbon molecules from large saturated hydrocarbon molecules.
See it on the paper →Two reactions of the alkenes ethene and propene are: combustion polymerisation. • • Describe one other chemical reaction of alkenes. Explain why alkenes can undergo this chemical reaction. reaction explanation
See it on the paper →Candidates should be reminded to read the question carefully. This question asked for observations. Many candidates described the reaction in terms of the breaking of the double bond and the name of the products instead of the observations that would be seen. Another common omission was for candidates to describe only the end result of decolourisation and not the initial colour that would be obser...
— Examiner report, February/March 2025, 0654/42 Q7(b)(i) (Cambridge)
The majority of candidates identified addition as the type of reaction. Polymerisation was a common incorrect answer.
— Examiner report, February/March 2025, 0654/42 Q7(b)(ii) (Cambridge)
Compound A was commonly correctly identified. Compound E was the most frequent incorrect response.
— Examiner report, May/June 2023, 0654/41 Q11(a)(iii) (Cambridge)
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Which reactions produce molecules of a different homologous series from the reactant molecules?
See it on the paper →State the colour change which is observed in the bromine solution during the process. colour changes from to .
See it on the paper →In process C ethene reacts with steam to produce ethanol, C 2 H 5 OH. A catalyst is used to increase the rate of reaction. State two other conditions necessary for this reaction.
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