Chemistry 9701/52 Oct Nov 2013 | Cambridge AS Level Past Papers With Mark Scheme

1. Enthalpy of solution for NH₄NO₃, prediction of temperature decrease during dissolution based on lattice energy and ion hydration enthalpy, and graphical representation of temperature vs. concentration.
2. Experimental design for NH₄NO₃ dissolution, including independent and dependent variables, apparatus setup for accurate temperature measurement, and safety precautions against fire and explosion hazards.
3. Solubility of NH₄NO₃ and experimental steps to test its variation with concentration; calculation of maximum solubility based on given solubility limits and preparation of concentration ranges for the study.
4. Transition temperature determination for Na₂SO₄·10H₂O to Na₂SO₄ through solubility experiments; plotting solubility vs. temperature and extrapolating curves to find the intersection.
5. Correction of mass recording errors in solubility experiments, recalculation of solubility for Na₂SO₄·10H₂O, and evaluation of percentage error differences due to balance zeroing issues.
6. Prediction of endothermic or exothermic nature of Na₂SO₄·10H₂O and Na₂SO₄ dissolutions based on temperature-solubility trends; explanation tied to Le Chatelier's principle and thermodynamic considerations.