Chemistry 9701/52 March 2018 | Cambridge AS Level Past Papers With Mark Scheme

1. Freezing Point Depression Experiment: Method for determining the freezing point depression of cyclohexane and calculating the molar mass of an organic compound using Beckmann apparatus, including measuring the volume and mass of cyclohexane and the accuracy of weight measurements.
2. Calibration and Measurement of Cyclohexane: Describing how to measure a precise amount of cyclohexane, discussing whether a burette is suitable for measuring volume based on density, and explaining the inaccuracies in using a container for mass measurements.
3. Data Analysis and Graphing: Calculating the ratio \\( B \\), plotting the relationship between \\( B \\) and the freezing point depression, identifying anomalous data points, and using graph data to calculate the mass of an unknown substance.
4. Gradient and Molar Mass Calculation: Determining the gradient of a graph, calculating the molar mass of an unknown substance, and explaining the relation between freezing point depression and molar mass.
5. Reaction with Potassium Manganate(VII): Determining the concentration of Fe2+ ions in a solution, calculating the mass of lawn sand needed for preparation, and determining the minimum volume of sulfuric acid required for the reaction.
6. Titration Method for Lawn Sand: Describing the titration setup and procedure for determining the percentage of FeSO4.7H2O in lawn sand, including proper techniques for preparing solution A and interpreting color changes at the endpoint.