Chemistry 9701/11 Oct Nov 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Chlorine Preparation and Oxidizing Agents: Explaining why MnO2 acts as an oxidizing agent in the preparation of chlorine and identifying the observed changes during the reaction.
2. Volatility of Halogens: Analyzing the trend in volatility of chlorine, bromine, and iodine down Group 17 based on intermolecular forces.
3. Disproportionation Reactions: Writing equations for chlorine’s disproportionation reactions with cold and hot sodium hydroxide and explaining the process.
4. Chlorine in Water Purification: Explaining the use of chlorine in water purification, particularly for disinfection purposes.
5. Free-Radical Substitution of Ethane: Identifying the conditions required for chlorine to undergo a free-radical substitution reaction with ethane and writing the overall reaction equation.
6. Oxides of Period 3 Elements: Discussing the bonding and structure of various Period 3 oxides and explaining the trend in their boiling points, with reference to their molecular structures.
7. Amphoteric Nature of Oxides: Explaining the concept of amphoterism with examples like Al2O3, and discussing its reactions with acids and bases.
8. Selenium and Sulfur Reactions: Identifying the reactions of selenium with fluorine and sodium hydroxide, using thermodynamic data to calculate bond enthalpies and explaining the variation in reactions with water.
9. Hydrocarbon Fuels and Combustion: Discussing the processes and reasons why hydrocarbons with low molecular mass are used as fuels and explaining incomplete combustion with an example.
10. Analysis of Thiophene: Explaining the combustion and enthalpy changes of thiophene, and performing calculations to determine the heat released and the enthalpy change of combustion.
11. Aldehyde Reactions: Discussing the reactions of phenylethanone, identifying products formed with reagents such as NaBH4 and NaOH, and describing the mechanisms involved.
12. Polymerization and NMR Analysis: Explaining the synthesis of polyamides and polyesters, identifying functional groups in organic compounds, and analyzing NMR spectra to determine molecular structures.
13. Mass Spectrometry and Chemical Identification: Using mass spectra and other analytical methods to identify and confirm the structures of organic compounds, with a focus on the reactions of aldehydes and alcohols.