Chemistry 9701/35 May June 2014 | Cambridge AS Level Past Papers With Mark Scheme

1. Titration of calcium hydroxide with diluted hydrochloric acid for concentration determination. Calculations for moles of \\(\\text{Ca(OH)}_2\\) and \\(\\text{HCl}\\), and error analysis for burette and volumetric flask readings. Explanation for concentration changes in limewater exposed to air.

2. Thermal decomposition of zinc carbonate to determine its percentage in a sample. Calculations for mass loss, zinc carbonate content, and suggestions for improving accuracy in decomposition experiments.

3. Identification of ions in zinc carbonate mixtures through qualitative analysis. Tests involving sodium hydroxide, ammonia, silver nitrate, and barium chloride to determine cation and anion identities with justification.

4. Qualitative tests for a mixture of two salts to identify ions through heating, reaction with silver nitrate and ammonia, and barium chloride with nitric acid. Use of observations and qualitative analysis notes for ion identification.