Chemistry 9701/21 May June 2015 | Cambridge AS Level Past Papers With Mark Scheme

1. Atomic structure analysis of particles with relative mass and charge, isotope abundance determination using mass spectrometry, and bonding with molecular formula calculations for tellurium chlorides.

2. Real gas behavior deviations from ideality under varying temperatures and pressures, intermolecular force effects, and relative molecular mass calculations using gas densities.

3. Chemical reactivity of nitrogen in atmospheric and combustion contexts, including equations for catalytic converter reactions and mechanisms for acid rain formation via nitrogen oxides.

4. Reaction mechanism of ethanal with hydrogen cyanide, formation of chiral centers with stereoisomerism, and role of catalysts in nucleophilic addition reactions.

5. Structural isomerism in alcohols with molecular formula \\( \\text{C}_4\\text{H}_{10}\\text{O} \\), reactivity with potassium dichromate and sulfuric acid, and identification of stereoisomers with displayed formulas.