Chemistry 9701/21 Oct Nov 2017 | Cambridge AS Level Past Papers With Mark Scheme

### 1. Haber Process and Bond Energies:
- Bond energy calculations using provided data for N≡N, H–H, and N–H bonds.
- Analysis of the effects of temperature on the rate and yield of ammonia production, referencing the Boltzmann distribution.
- Equilibrium calculations for the reaction of nitrogen and hydrogen to form ammonia at a given pressure.

### 2. Periodic Trends and Ionization Energies:
- Explanation of the general increase in ionization energies across Period 3.
- Sketching ionization energy graphs and explaining the exceptions in the trends for magnesium and aluminum, as well as phosphorus and sulfur.

### 3. Chemical Reactions and Compounds:
- Identifying and explaining the properties and reactions of Period 3 chlorides, including writing equations and explaining observations for substances like L and M (e.g., SiCl₄ and PCl₅).
- Discussing the hydrolysis reactions of various chlorides and their effect on pH.

### 4. Organic Chemistry Reactions:
- Identifying reagents and reaction mechanisms for reactions involving 1-bromobutane, such as substitution, hydrolysis, elimination, and oxidation reactions.
- Explaining the SN2 mechanism for halogenoalkanes and the differences when treating tertiary halogenoalkanes like 2-bromo-2-methylpropane.

### 5. Stereoisomerism:
- Understanding the concept of stereoisomers and applying it to reactions with alkenes, such as the formation of isomers when but-1-ene reacts with HCl.