Chemistry 9701/33 March 2021 | Cambridge AS Level Past Papers With Mark Scheme

1. Titration to Determine Metal in Hydrogencarbonate: Experiment to identify the Group 1 metal (M) in a metal hydrogencarbonate by titrating a solution of the hydrogencarbonate with sulfuric acid.
2. Calculations of Moles and Concentration: Perform calculations to determine the moles of H2SO4 used, concentration of MHCO3 in solution, and the relative formula mass (Mr) of the hydrogencarbonate.
3. Relative Atomic Mass Calculation: Using titration data to calculate the relative atomic mass (Ar) of the metal (M) in the hydrogencarbonate and identify the metal.
4. Experimental Accuracy and Errors: Calculation of the maximum percentage error in the volume of solution used and discussion on the choice of measuring instruments (pipette vs burette).
5. Thermal Decomposition of Sodium Carbonate: Determining the relative formula mass of metal hydrogencarbonate by thermal decomposition and comparing results with titration data.
6. Gas Production and Anion Identification: Identifying gases produced and anions present during thermal decomposition, and writing ionic equations for the reactions.
7. Procedure Optimization: Suggestions for improving the procedure for more accurate results, such as reducing errors and ensuring consistent experimental conditions.