CAIE A Level Chemistry 9701 · Reaction kinetics
Ethene reacts with hydrogen to form ethane: . The reaction is very slow at room temperature in the absence of a catalyst. A nickel catalyst is effective for this reaction.
Compare the reaction pathway in the presence and absence of the nickel catalyst, in terms of the mechanism, the activation energy, and the effect on the rate.
6 marks, so the mark scheme is looking for about 6 separate creditworthy points. Making the same point twice in different words earns it once.
Compare means: Give similarities or differences between two things, and say which side each point belongs to. Write each point as a pair, for example: A is X, whereas B is Y. Two separate descriptions rarely earn the marks.
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