Chemistry 9701/52 May June 2017 | Cambridge AS Level Past Papers With Mark Scheme

1. Lead Oxide Experiment: Hazards associated with handling lead oxide include toxicity and environmental harm. Precautions include using fume hoods and wearing gloves to minimize exposure.
2. Experimental Method: The procedure involved heating lead oxides in a controlled environment, measuring masses before and after heating, and calculating the ratio of mass of lead that combined with oxygen.
3. Dalton's Law and Mass Ratios: Using the experimental results, the mass ratios of lead in the compounds were calculated, and the results were compared with Dalton’s Law, determining if the law holds.
4. Independent and Dependent Variables: Identifying the independent variable (amount of lead oxide) and the dependent variable (reaction time or mass of lead formed).
5. Empirical Formula Calculation: The empirical formula of lead oxide was calculated based on experimental data and stoichiometric relationships.
6. Reliability and Experimental Adjustments: Addressing the importance of cooling with methane gas and suggesting improvements for ensuring complete reduction of lead oxide.
7. Manganese Content Analysis: Using a spectrophotometer to measure the absorbance of MnO4– solutions, determining the manganese concentration, and calculating the mass and percentage of manganese in steel samples.
8. Titration and Oxidizing Agents: Understanding the importance of removing strong oxidizing agents before titration, using iron(II) ions to titrate MnO4–, and explaining the titration process in detail.