Chemistry 9701/35 May June 2021 | Cambridge AS Level Past Papers With Mark Scheme

1. Practical titration for determining the relative formula mass (Mr) of a monoprotic acid (HX) using sodium carbonate as the titrant.
2. Calculation of moles of sodium carbonate and monoprotic acid, along with deriving the equation for their reaction, and computing the relative formula mass of HX.
3. Determination of the molecular identity of an element (E) in the monoprotic acid and evaluation of the maximum error in mass recording during the experiment.
4. Performing experiments with silver nitrate to test the solubility of a compound and analyzing the potential errors due to the choice of methyl orange indicator.
5. Mass loss calculation for the hydrated salt to determine the percentage by mass of water of crystallization, including assumptions made in the calculation.
6. Analysis of cations and anions in a sample, including identifying the ions through reactions with NaOH, NaCl, and sulfuric acid, and calculating the relative formula mass of the sample.
7. Detailed observations and ionic equations for reactions involving sulfur and sodium hydroxide, including tests for solubility and crystallization.
8. Practical testing using aqueous reagents to determine the identity and characteristics of an unknown compound, including further experimentation with NaOH and NaCl.