Chemistry 9701/36 Oct Nov 2017 | Cambridge AS Level Past Papers With Mark Scheme

1. Titration Methods: Determining the percentage by mass of ethanedioic acid in a mixture by performing two titrations: one with potassium manganate(VII) and one with sodium hydroxide.
2. Reaction Equations and Moles Calculation: Writing equations for reactions between ethanedioic acid and sodium hydroxide, calculating moles of ethanedioate and ethanedioic acid from titration data.
3. Mass Calculations: Using titration results to calculate the mass of sodium ethanedioate and ethanedioic acid in a sample, and determining the percentage by mass of ethanedioic acid.
4. Effect of Hydrated Ethanedioic Acid: Explaining the impact of using hydrated ethanedioic acid instead of anhydrous on titration volume and percentage calculations.
5. Improvement of Accuracy: Analyzing whether reducing concentrations of reagents would improve titration accuracy, with supporting reasoning.
6. Qualitative Analysis: Identifying the metals in various solutions through a series of reactions and observing color changes, precipitate formation, and solubility behaviors.