Chemistry 9701/33 Oct Nov 2020 | Cambridge AS Level Past Papers With Mark Scheme

1. Rate of reaction study for iodide ions with iron(III) ions, involving starch indicator, sodium thiosulfate reduction of iodine, and calculation of reaction rates.

2. Graphical analysis of reaction rate versus iodide ion concentration, identification of anomalous points, and determination of reaction times for varying conditions.

3. Ionic equations for thiosulfate reactions, proportionality of iodide concentration to reaction rate, and comparative analysis of experimental setups for procedural efficiency.

4. Qualitative tests for cation and anion identification in salts using reagents like sodium hydroxide, hydrogen peroxide, and chloride, with detailed observations of precipitates and gas formation.

5. Use of stoichiometry and graphical data to predict reaction times and conditions for optimizing reaction rates in controlled experiments.

6. Analysis of sulfuric acid roles in reactions, detection of halides using qualitative reagents, and differentiation between salts based on ion-specific tests and chemical behavior.