Chemistry 9701/35 Oct Nov 2012 | Cambridge AS Level Past Papers With Mark Scheme

1. Measurement of temperature change during magnesium and hydrochloric acid reaction. Graphical analysis for extrapolated temperature rise, error identification (thermometer accuracy and room temperature), and procedural improvements.

2. Titration of hydrochloric acid (\\( \\text{FA 2} \\)) with sodium carbonate (\\( \\text{FA 3} \\)): moles of sodium carbonate, concentration of hydrochloric acid, and back-calculation for \\(\\text{FA 1}\\). Stoichiometric relationships and preparation details for accurate titration results.

3. Qualitative analysis of solutions (\\( \\text{FA 4} \\), \\( \\text{FA 5} \\), \\( \\text{FA 6} \\)) and solid (\\( \\text{FA 7} \\)) containing transition metal ions. Reaction observations with \\(\\text{HCl}\\), \\(\\text{NH}_3\\), \\(\\text{AgNO}_3\\), and \\(\\text{KI}\\). Identification of ions in \\(\\text{FA 6}\\) and oxidation state changes during reactions. Evidence of \\(\\text{Fe}^{2+}\\) oxidation using confirmatory tests.