Chemistry 9701/42 May June 2010 | Cambridge AS Level Past Papers With Mark Scheme

1. Phenacyl Chloride Reaction: Nucleophilic substitution with NaOH to form products, analysis of the rate equation, and description of the reaction mechanism.
2. Solubility of Group II Sulfates: Trend in solubility down the group, related enthalpy calculations for the dissolution of Mg(OH)₂ and Sr(OH)₂, and comparison of solubility in hot water.
3. Electronegativity and Dipole Moments: Comparison of SF₄ and SiF₄, reasoning behind the difference in dipole moments, and reaction equations for chlorides of B and Si with water.
4. Reactions of Fe²⁺ and KMnO₄: Observations during redox reactions with iron(II) and permanganate, explanation of stability of Fe²⁺ in acidic solutions.
5. Bonding and Molecular Structures: Discussion of bonding in SiCl₄, predictions on dipoles in molecules like BCl₃, PCl₃, SF₆, and structural insights into compounds like SiCl₄.
6. Electrochemical Reactions: Calculation of voltage produced by lead-acid cells, comparison with nickel-metal hydride batteries, and possible advantages in battery design and power usage.
7. Protein Structure: Explanation of protein structures, including primary and tertiary structures, with specific examples from keratin and silk, and stabilization of β-pleated sheets.
8. Electrophoresis of Amino Acids: Investigation of amino acid properties, interpretation of electrophoresis results, and explanation of behavior during the experiment.
9. Recycling and Environmental Impact: Discussion of recycling importance, including materials like glass, steel, and plastics, focusing on energy and resource conservation.