Chemistry 9701/52 May June 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Determining the Percentage of MnCO3 in Rhodochrosite: The procedure for calculating the percentage of MnCO3 in rhodochrosite using the volume of CO2 produced during a reaction with hydrochloric acid.
2. Experimental Setup for Gas Collection: Designing an apparatus to collect CO2 over water, identifying potential weaknesses in the procedure, and suggesting changes in the apparatus to improve accuracy.
3. Titration Method for Copper in Brass: Writing the ionic equation for the reaction between copper and nitric acid, calculating the percentage error in mass measurements, and discussing the precautions when using concentrated nitric acid.
4. Absorbance Measurement for Cu2+ Concentration: Using a colorimeter to measure the concentration of Cu2+ ions in a solution, creating a calibration graph, and interpreting the results for the percentage of copper in a brass nail.
5. Copper (II) Nitrate Preparation and Dilution: Calculating the mass of copper(II) nitrate required for preparing a specific concentration and volume of solution, and completing a table of volumes for a series of dilutions.
6. Determining the Concentration of Copper in a Brass Nail: Using calibration data and absorbance measurements to calculate the concentration of Cu2+ ions in a brass nail sample and determining the percentage of copper.
7. Method for Calculating the Percentage of Copper: Final calculation of the percentage of copper in a brass nail using the absorbance data, calibration graph, and known mass of the sample.