Chemistry 9701/22 Oct Nov 2017 | Cambridge AS Level Past Papers With Mark Scheme

### 1. Properties of Chlorides:
- Predicting molecular shapes and bond angles for chlorides like AlCl₃ and PCl₃.
- Explaining the trends in melting points of chlorides (e.g., SiCl₄ vs. NaCl and SiCl₄ vs. PCl₃), including the reasoning behind the differences in melting points.

### 2. Equilibrium and Enthalpy:
- Determining the enthalpy change for the formation of PCl₅ using known enthalpies of formation for other compounds.
- Explaining the effects of temperature on the rate and extent of decomposition of PCl₅ in a reversible reaction.

### 3. Group 2 and Group 17 Trends:
- Discussing trends in ionization energy, melting points, and the reactivity of elements in Groups 2 and 17.
- Analyzing reactions involving barium (Ba), such as its reactions with water, air, and sulfuric acid.

### 4. Organic Reactions and Mechanisms:
- Understanding various organic reactions such as dehydration, substitution, and addition reactions involving compounds like methylpropan-2-ol.
- Describing the SN1 and SN2 mechanisms, and understanding structural isomerism and stereoisomerism in organic compounds.

### 5. Polymerization:
- Identifying the polymerization process for alkenes and drawing the repeat unit for poly(alkenes).
- Discussing the environmental issues related to the disposal of poly(alkenes).