Chemistry 9701/33 Oct Nov 2013 | Cambridge AS Level Past Papers With Mark Scheme

1. Determination of iron(II) salt relative formula mass using titration with potassium manganate(VII). Moles of \\(\\text{KMnO}_4\\) and \\(\\text{Fe}^{2+}\\), reaction stoichiometry, and error analysis for pipette and weighing.

2. Hydrated barium chloride formula calculation (\\(\\text{BaCl}_2.x\\text{H}_2\\text{O}\\)) using mass differences after heating. Moles of anhydrous \\(\\text{BaCl}_2\\) and water loss for determining \\(x\\), consistency check between experiments, and procedural improvements for complete dehydration.

3. Qualitative analysis of hydrated barium chloride (\\(\\text{FA 5}\\)) and an iron(II) salt (\\(\\text{FA 6}\\)) with additional ions. Tests with sodium hydroxide, hydrochloric acid, and heating to identify ions. Ionic equations for reactions and observations.

4. Identification of ions in solutions (\\(\\text{FA 7, FA 8, FA 9}\\)) using mixing tests with sulfuric acid and among themselves. Analysis of precipitates and reactions to deduce cations and anions with qualitative analysis notes.