Chemistry 9701/52 March 2017 | Cambridge AS Level Past Papers With Mark Scheme

1. Decomposition of Sodium Hydrogencarbonate: Investigating the enthalpy change for the decomposition of sodium hydrogencarbonate using magnesium, calculating the heat energy evolved, and determining the enthalpy change for the reaction.
2. Method and Apparatus Setup: Describing the procedure for accurately measuring the mass of reactants and the temperature change during reactions, drawing labeled diagrams of the experimental setup, and calculating the enthalpy change from the experimental data.
3. Temperature Measurements and Graph Analysis: Analyzing the theoretical temperature rise based on the experimental graph, calculating the enthalpy change from the experimental data, and explaining why certain temperature readings were anomalous.
4. Experiments with Different Acids: Comparing the methods and results when using hydrochloric acid and ethanoic acid, calculating the energy needed for ionization, and explaining why different acids exhibit different behaviors in reactions.
5. Preparation of Standard Solutions: Calculating the mass of a compound required to prepare a solution of known concentration, explaining the procedure for making the solution, and describing the apparatus needed for accurate measurements.
6. Colorimetry and Transition Metal Complexes: Using colorimetry to determine the concentration of complex ions formed between iron(III) and 2-hydroxybenzoate ions, analyzing the relationship between absorbance and concentration, and suggesting the formula of the resulting complex.
7. Effect of Experimental Changes on Results: Suggesting how changing the volumes of reactants would affect the absorbance in colorimetry experiments, and understanding the relationship between absorbance and concentration using the Beer-Lambert law.