CAIE A Level Chemistry 9701 · Reaction kinetics
Ethene reacts with hydrogen to form ethane. The uncatalysed reaction has a high activation energy, but in the presence of a nickel catalyst the reaction proceeds rapidly at a lower temperature.
Compare the catalysed and uncatalysed pathways for this reaction. In your answer, refer to the activation energy, the reaction mechanism, and the Boltzmann distribution of molecular energies.
5 marks, so the mark scheme is looking for about 5 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.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.