Chemistry 9701/21 May June 2021 | Cambridge AS Level Past Papers With Mark Scheme

1. Properties and decomposition of ethanedioic acid; empirical formula derivation, carbon atom calculations, and calcium ethanedioate thermal reactions.

2. Electronegativity comparisons, intermolecular forces in N₂ and CO, reactivity trends, and ideal gas behavior conditions for small diatomic molecules.

3. Reactions of sodium halides with sulfuric acid; chemical identification of products, solid iodine formation, and comparative reactivity differences between NaCl and NaI.

4. Oxidation and reduction in bromine-methanoic acid reactions; rate calculations, reaction mechanisms, and graphical changes with temperature variations.

5. Hydrocarbons in naphtha: cracking process for ethene and propene formation, functional group identification in oxidation products, and polymer chemistry involving water-absorbing properties.

6. Hydration of propene to alcohols: reaction mechanisms, carbocation stability analysis, and elimination reactions for brominated alkanes.

7. Environmental impacts of polymer disposal: greenhouse gas emissions, secondary pollution, and problems associated with synthetic polymer combustion.