Chemistry 9701/42 March 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Nitrogen Oxide Reactions: Investigating the formation of dinitrogen monoxide (N2O) and dinitrogen trioxide (N2O3) from nitrogen monoxide (NO), calculating entropy change (ΔS), and interpreting the impact of reaction conditions.
2. N2O3 Dissociation and Kp Calculation: Writing Kp expression for N2O3 dissociation, calculating equilibrium pressures, and determining the equilibrium constant (Kp).
3. Rate Determination of NO and O2 Reaction: Determining reaction order with respect to NO and O2, deriving the rate equation, and calculating the rate constant with units.
4. Iron and NO Reaction: Understanding co-ordination changes in iron complexes, including the formation of Fe(CO)2(NO)2 and predicting the geometry of coordination complexes.
5. Brass Composition and Titration: Using thiosulfate titration to determine copper content in brass, calculating percentage composition, and understanding electrochemical calculations.
6. Mass Spectrometry and NMR: Analyzing ketamine and neramexane using mass spectrometry, calculating molecular composition, and assigning NMR peaks based on structural data.