Chemistry 9701/34 May June 2016 | Cambridge AS Level Past Papers With Mark Scheme

1. Determination of x in Na₂BxO₇·10H₂O through titration, calculation of moles of HCl, borax, and Mr of borax, and calculation of x using periodic table data.
2. Analysis of decomposition reaction of MgCO₃·Mg(OH)₂·2H₂O, calculation of moles of MgO, experimental and theoretical Mr comparison, and evaluation of formula accuracy based on percentage error.
3. Qualitative analysis of FB 5, FB 6, and FB 7 solutions; observation of reactions with magnesium ribbon, sodium hydroxide, and potassium iodide, with identification of ions based on observations.
4. Experimental determination of the composition of FB 8 through heating and reaction with HCl, identification of gaseous products, and inference of cation and anion identities.
5. Error analysis and accuracy improvement in practical procedures, impact of balance error on percentage calculations, and advantages of separate calculations for multiple experiments.
6. Identification and testing of anions and cations using precipitate formation, solubility tests, and gas evolution analysis from qualitative analysis notes and provided periodic table data.