Chemistry 9701/11 May June 2011 | Cambridge AS Level Past Papers With Mark Scheme

1. Reactions of oxides like phosphorus(V) oxide, sulfur(IV) oxide, and nitrogen dioxide with water, including disproportionation reactions leading to the formation of acids.
2. Combustion of a mixture of methane, ethane, and hydrogen sulfide, and the necessity of removing hydrogen sulfide from natural gas before industrial combustion.
3. Use of ethanolamine to remove hydrogen sulfide, mass calculations, and the reversal of the reaction to recover H₂S.
4. Explanation of the color and nature of transition metal complexes, and an exploration of copper salts with ammonia and water.
5. Copper recovery from ores, using titration to estimate Cu²+ concentration in a leach solution.
6. Organic reactions involving thymol, menthol, and menthone, and tests to identify each compound.
7. Reactions involving ethylbenzene, with a focus on halogenation and nitration steps, along with reagent identification.
8. Chlorine manufacturing through brine electrolysis, focusing on anode reactions, electrode potentials, and related calculations.
9. Production of sodium chlorate(V) by electrolysis, including current calculations and the overall ionic equation.
10. Synthesis and identification of compounds from ethene, along with reaction conditions, and the breakdown of polymers for digestion.

1. Rate of Decomposition of Hydrogen Peroxide: Investigating how the rate of decomposition depends on hydrogen peroxide concentration, using manganese(IV) oxide as a catalyst. The rate is hypothesized to increase with concentration.
2. Apparatus for Measuring Oxygen Volume: Using standard laboratory equipment like burettes, conical flasks, and a gas collection system, ensuring no oxygen escapes during measurements.
3. Experiment Design: Detailed steps on preparing hydrogen peroxide solutions, conducting titrations with potassium iodide, and using manganese(IV) oxide for catalysis.
4. Calculating Rate of Reaction: Employing titration data to determine the rate of reaction by measuring the time for fixed volumes of oxygen to be collected.
5. Graphical Representation: Using a graph to plot concentration versus rate of reaction, identifying the relationship between these variables.
6. Error Analysis: Acknowledging potential errors in titration readings and suggesting procedural improvements for accuracy.