Chemistry 9701/31 May June 2015 | Cambridge AS Level Past Papers With Mark Scheme

1. Determination of Fe²⁺ concentration using titration with potassium manganate(VII). Calculation of Fe²⁺ moles, concentration, and hydrated ammonium iron(II) sulfate mass required for solution preparation.

2. Heat measurement for the reaction of Zn and CuSO₄. Temperature-time relationship, theoretical temperature rise determination, enthalpy calculation, and CuSO₄ concentration estimation. Analysis of temperature measurement error and impact of reactant proportions on accuracy.

3. Qualitative analysis for FA2 and FA6. Observations for precipitate formation and solubility in reagents like sodium carbonate, sulfuric acid, sodium hydroxide, and ammonia. Identification of FA6 ions, supplementary test proposals, and justification.