Chemistry 9701/53 Oct Nov 2013 | Cambridge AS Level Past Papers With Mark Scheme

1. Solubility of air in water influenced by temperature based on Le Chatelier's principle; prediction of solubility trends with temperature and sketch graph representation.
2. Investigation of H₂O₂ decomposition with MnO₂ and PbO₂ catalysts; apparatus setup, calculation of maximum H₂O₂ volume, identification of measurements to evaluate catalyst efficiency, and addressing catalyst control variables.
3. Safety measures for handling toxic catalysts like MnO₂ and PbO₂, including hazard precautions and experimental safety protocols to prevent inhalation or skin exposure.
4. Boiling point and vapor-liquid equilibrium for CCl₄ and C₂H₂Cl₄ mixtures; calculation of mole fractions, plotting of liquid and vapor composition against temperature, and graphical analysis of anomalies.
5. Distillation of CCl₄ and C₂H₂Cl₄, identifying which liquid distills first based on relative boiling points and volatility; explanation supported by vapor-liquid equilibrium data.
6. Percentage error analysis in temperature measurements for boiling point determination, and implications of reduced thermometer calibration precision on experimental accuracy.