Chemistry 9701/33 May June 2021 | Cambridge AS Level Past Papers With Mark Scheme

1. Determining the concentration of sodium chlorate(I) in bleach through titration with thiosulfate and iodide, involving calculations for moles, concentration, and excess reagents.
2. Calculation of heat energy change and relative formula mass for hydrated sodium thiosulfate, using enthalpy change of hydration.
3. Investigation of the effect of changes in water volume on the calculations and accuracy of results in an experiment involving hydrated sodium thiosulfate.
4. Qualitative analysis of salts containing cations and anions, involving various tests such as heating, dissolving in water, and adding reagents like silver nitrate, with the identification of ions.
5. Use of reagents like potassium manganate(VII) and magnesium to identify substances and test for reactions in aqueous solutions.
6. Observations of reactions and changes when different acids and salts are mixed, and the identification of substances based on experimental results.
7. Conducting tests for gases and understanding their identification, including ammonia, carbon dioxide, and hydrogen, with the appropriate reactions and outcomes.
8. Analysis of a reaction sequence involving copper(II) sulfate and iodide, predicting possible reactions and explaining observed results with electrode potentials.