Chemistry 9701/53 May June 2021 | Cambridge AS Level Past Papers With Mark Scheme

1. Planning an experiment to determine the best metal oxide catalyst for the decomposition of hydrogen peroxide, including identifying independent and dependent variables and controlling factors.
2. Design and preparation of apparatus for accurately measuring oxygen produced during the reaction.
3. Determination of the initial rate of reaction based on recorded measurements and calculation of the rate using those data.
4. Discussion of methods to ensure the reliability of experimental results and suggested alternative methods for investigating reaction rates without gas collection.
5. Identifying and addressing experimental weaknesses, such as inaccuracies in measurement and the need for improved precision in titrations.
6. Titration of a mixture of Fe2+ and Fe3+ to determine the total mass of iron ions and the percentage by mass of Fe3+ in the solution, including calculations and analysis of experimental data.