Chemistry 9701/31 May June 2020 | Cambridge AS Level Past Papers With Mark Scheme

1. Determining the Relative Formula Mass of a Hydrated Salt: The procedure for preparing a solution of a hydrated salt, performing a titration with potassium manganate(VII), and calculating the relative formula mass of the hydrated salt.
2. Calculations Involving Moles and Concentration: Determining the moles of potassium manganate(VII), the concentration of the hydrated salt, and calculating the relative formula mass using titration data.
3. Determining Enthalpy Change of Solution for Sodium Carbonate: Performing an experiment to measure the energy produced when sodium carbonate dissolves in water, and calculating the enthalpy change for the dissolution process.
4. Improving Experimental Accuracy: Suggestions to minimize errors in the temperature measurement and improve accuracy, including possible modifications to the procedure and calculating the percentage error in the experiment.
5. Qualitative Analysis for Identifying Cations and Anions: Conducting tests to identify cations and anions in hydrated salts, determining the water of crystallization, and calculating the number of moles of water in the compound.
6. Experimental Procedure Improvements: Proposing improvements to the experimental setup to reduce heat loss and improve the accuracy of results when measuring temperature changes in reactions involving hydrated salts.