Chemistry 9701/35 May June 2011 | Cambridge AS Level Past Papers With Mark Scheme

1. Titration and Reaction Calculations: Determining the percentage by mass of water in borax crystals through titration with hydrochloric acid. Includes calculating the concentration of hydrochloric acid, moles of borax, and the empirical formula of borax from titration data.
2. Ionization Energies and Atomic Trends: Analysis of ionization energies across elements, including periodic trends, and explanation of variations based on atomic structure and electron configurations.
3. Thermal Reactions and Decomposition: Detailed calculations of heat production and temperature changes in reactions involving sodium carbonate and sodium hydrogencarbonate, including using Hess’s Law for enthalpy changes.
4. Chemical Identification and Analysis: Identifying anions (e.g., nitrites, halides) and cations (e.g., aluminum, ammonium) through qualitative tests, precipitation, and solubility behaviors.
5. Chemical Synthesis and Reaction Mechanisms: Understanding functional group transformations and reaction pathways in organic chemistry, including esterification, oxidation, and reduction mechanisms.