Chemistry 9701/52 March 2016 | Cambridge AS Level Past Papers With Mark Scheme

1. Determination of the order of reaction with respect to iodine using titration of unreacted iodine with thiosulfate, inclusion of reaction variables and controlled conditions.

2. Calculation of required apparatus volume and mass of propanone for standard solution preparation, with rationale for experimental procedures and solutions order.

3. Experimental enthalpy change of combustion of ethanol using specific apparatus; processing results, plotting graphs, and identifying anomalies in energy data.

4. Variables affecting reaction kinetics, including the impact of temperature and the choice of neutralizing agent (sodium hydrogencarbonate vs. sodium hydroxide).

5. Gradient determination from energy vs. ethanol burned graph; evaluation of measurement errors, enthalpy results comparison to accepted values, and experimental discrepancies.

6. Analysis of iodine concentration changes over time to confirm first-order reaction; examination of the effect of temperature on reaction order with theoretical justification.