Chemistry 9701/42 March 2018 | Cambridge AS Level Past Papers With Mark Scheme

1. Solubility and Decomposition of Group 2 Compounds: Understanding the variation in solubility of hydroxides down Group 2, explaining factors affecting solubility, and writing equations for the thermal decomposition of strontium peroxide and barium ethanedioate.
2. Halogen Reactivity: Explaining the trend in halogen reactivity as oxidizing agents using electrode potentials, writing reactions, and calculating the cell potential for halogen and hydroxide reactions.
3. Titration and Ka Calculations: Performing a titration to determine whether an acid is monoprotic or diprotic, calculating the pH of HCN, and using the Ka value to determine the concentration of H+ ions.
4. Ammonia and Butylamine Chemistry: Understanding partition coefficients and how the solubility of butylamine compares to ammonia, as well as explaining basicity and reactions of amines.
5. Chromium Chemistry: Completing the electronic configuration of chromium and its ions, and analyzing the reactions of copper and cobalt with various reagents, including determining complex ion charges and isomerism.
6. Polymerization and Amide Bonds: Discussing the process of polymerization, explaining entropy changes during addition and condensation polymerization, and calculating the enthalpy change for amide bond formation.
7. Synthesis and Functional Group Reactions: Suggesting synthetic routes for the production of various compounds like cuminyl alcohol and explaining reaction mechanisms such as nucleophilic substitution and ester formation.
8. Identification of Organic Compounds: Using spectroscopic data to identify functional groups in organic compounds, including explaining NMR spectra and predicting molecular structures and reaction mechanisms.