Chemistry 9701/41 May June 2010 | Cambridge AS Level Past Papers With Mark Scheme

1. Phosphorus and Sulfur Combustion: Observations and balanced equations for the combustion of phosphorus and sulfur in air, producing P₄O₁₀ and SO₂, respectively.
2. Phosphorus Allotropes: Production of white phosphorus from calcium phosphate, with a balanced reaction equation. Discussion on the different structures and bonding in white and red phosphorus, as well as their physical properties like solubility and melting points.
3. Transition Elements Characteristics: Chemical properties of transition elements, their distinct behaviors compared to Group II elements, including formation of colored compounds, complex ion formation, and variable oxidation states.
4. Nickel Chemistry: Reactions of Ni²⁺ with ammonia, explaining the formation of a grey-green precipitate that dissolves in excess ammonia to form a blue-violet solution.
5. Quantitative Estimation of Nickel: Calculation of the percentage of nickel in a sample of nickel using dimethylglyoxime (DMG) and precipitation methods.
6. Tin and Lead Oxides: Differences in behavior of Sn(IV) and Pb(IV) oxides on heating, and reactions involving PbCl₄ and SnCl₄ with KI(aq) for the evolution of iodine gas.
7. Dichlorocarbene Formation: Electron arrangement in CCl₂ and the reaction with water to produce carbon monoxide and acidic solution, with the predicted molecular shape of CCl₂.
8. Acyl Chlorides: Reactions of benzoyl chloride with ethanol and ammonia, identifying the products and their functional groups, and the reactions of acyl chlorides with amines.
9. Intermolecular Interactions in Water: Analysis of interactions between hydrophilic and hydrophobic drugs and water within liposomes, and the explanation of pH differences in diamines versus drug molecules.
10. Drug Delivery: Explaining the importance of liposomes and polyethylene glycol (PEG) in drug delivery systems, and the advantages of smaller drug doses for better targeting and reduced side effects.