Chemistry 9701/32 May June 2017 | Cambridge AS Level Past Papers With Mark Scheme

1. Thermal Stability and Decomposition of Carbonates: Explaining the variation in thermal stabilities of Group 2 carbonates and comparing the stability of sodium carbonate and magnesium carbonate.
2. Decomposition of Hydrogencarbonates: Writing the equation for the decomposition of potassium hydrogencarbonate and predicting the temperature at which NaHCO3 or KHCO3 decomposes.
3. Lattice Energy Calculations: Using provided data to calculate the lattice energy of potassium oxide (K2O) and comparing it to sodium oxide, with explanations based on ionic radii.
4. Titration of Organic Acids: Performing a titration to determine the relative formula mass of an organic acid, calculating its concentration, and identifying the anion based on titration data.
5. Effect of Dilute Sodium Hydroxide on Titration Results: Analyzing the effect of using a less concentrated sodium hydroxide solution on the calculation of relative formula mass and the identification of the acid.
6. Enthalpy Change of Neutralization: Determining the enthalpy change of neutralization for a different acid, using titration data, calculating heat energy and moles of NaOH neutralized.
7. Qualitative Analysis of Acids and Cations: Identifying acids and cations in solutions by performing a series of tests, analyzing observations like color changes, precipitates, and gas formation, and writing equations for these reactions.
8. Electrophoresis of Amino Acids and Peptides: Analyzing the results of electrophoresis to identify amino acids and peptides, understanding how the pH of the buffer affects their movement.
9. Organic Synthesis Reactions: Identifying and drawing structures for organic compounds in synthesis routes and discussing mechanisms such as nucleophilic substitution and electrophilic addition.