Chemistry 9701/53 Oct Nov 2021 | Cambridge AS Level Past Papers With Mark Scheme

1. Discussion on why it is not possible to measure the enthalpy change for the decomposition of potassium hydrogencarbonate directly.
2. Calculation of mass and percentage error for 0.0250 moles of KHCO3 and K2CO3.
3. Energy changes and enthalpy calculations for the reactions of KHCO3 and K2CO3 with HCl.
4. Use of a cycle to calculate the enthalpy change of the decomposition reaction of KHCO3.
5. Suggestions on possible reasons for discrepancies between experimental and textbook values of enthalpy change.
6. Improvements in the experimental procedure to reduce error and enhance accuracy.
7. Identification of the apparatus needed for volumetric measurements and safety precautions in experiments.
8. Apparatus setup and data handling for measuring the rate of reaction between calcium carbonate and hydrochloric acid.
9. Plotting and analysis of experimental data on carbon dioxide production in reaction studies.
10. Calculation of the rate constant and discussion on the effect of temperature on reaction rates.
11. Investigation of the effect of hydrochloric acid concentration on the reaction rate using antacid tablets.
12. Suggestions for improving the reliability of experimental results and identifying the dependent variable.