Chemistry 9701/31 Oct Nov 2012 | Cambridge AS Level Past Papers With Mark Scheme

1. Sodium thiosulfate and HCl reaction rate determination, time vs. concentration relationship, graphical analysis of reaction rate against Na₂S₂O₃ concentration.
2. Effect of vessel size on reaction visibility times, experimental parameters for rate consistency, proportionality check between rate and reactant concentration.
3. Calculation of sodium thiosulfate concentration in diluted solutions, reaction completion uncertainties, and adjustments to minimize measurement errors.
4. Identification of cations and anions in qualitative analysis, use of carbonate precipitation, silver nitrate, and ammonia for halide differentiation.
5. Analysis of qualitative tests for anions and cations using solubility, precipitate formation, and specific reagents for confirmation of halide presence.