Chemistry 9701/51 May June 2017 | Cambridge AS Level Past Papers With Mark Scheme

1. Enthalpy Change and Heat Pack Experiment: Determining the enthalpy change when anhydrous calcium chloride dissolves in water, interpreting the experimental setup, and calculating the mass of calcium chloride required to produce a specific temperature rise in a heat pack.
2. Graphing and Data Interpretation: Plotting a graph to show the relationship between the concentration of sucrose and the observed angle of rotation, identifying anomalous data, and calculating the specific rotation of sucrose.
3. Preparation of Standard Solutions: Calculating the mass of sucrose needed to prepare a solution of known concentration and describing the procedure for accurately preparing the solution.
4. Solution Dilution and Apparatus: Calculating the volume of a concentrated sucrose solution required to make a diluted solution and selecting appropriate apparatus for measurement.
5. Anomalous Data and Experiment Errors: Identifying errors in solution preparation that may lead to anomalous data and suggesting methods for improving accuracy in future experiments.
6. Concentration Determination via NMR: Using NMR data and the relationship between optical rotation and concentration to determine the concentration of an unknown sucrose solution.
7. Improvement in Experimental Accuracy: Proposing methods to ensure accurate concentration measurement when reusing expensive glass cells in polarimeter experiments.
8. Effect of Cell Length on Optical Rotation: Predicting the observed angle of rotation for a solution using a different glass cell length, considering the effect of cell length on optical rotation measurements.