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

1. Trends in Periodicity:
- Atomic radius trends across Period 3 elements (Na to Cl).
- Explanation of the relationship between atomic radius and nuclear charge.
- Understanding the difference in ionic radii between Mg²⁺ and S²⁻ ions.

2. Phosphorus Chemistry:
- Reaction of phosphorus with oxygen to form compounds like P₄O₁₀.
- Observations and identification of compounds formed when phosphorus reacts with chlorine.
- Understanding of phosphorus halides like PCl₅.

3. Lanthanoids:
- The bonding and structure of lanthanoid metals like cerium.
- Physical properties of cerium(IV) oxide (CeO₂), which is used in ceramics.
- Calculation of the relative isotopic mass of cerium isotopes.

4. Hydrogen Halides:
- Understanding bond polarity in hydrogen halides (HF to HI).
- Explanation of boiling point differences, including the effect of hydrogen bonding in HF.
- Thermal stability and the trend of bond strength in the hydrogen halides.

5. Acid-Base Chemistry:
- Application of Brønsted-Lowry theory to identify acids and bases in reactions.
- Explanation of reactions involving sodium chloride, sodium iodide, and sulfuric acid.

6. Reactions and Thermodynamics:
- Calculation of enthalpy changes for reactions, including the preparation of hydrogen chloride.
- Understanding of equilibrium reactions and how changes in temperature or pressure affect equilibrium compositions.
- Calculation of mole fractions and partial pressures in equilibrium mixtures.

7. Organic Chemistry:
- Reactions of organic compounds, such as the conversion of 1-bromobutane into various products.
- Identification of polymers formed from alkenes.
- Mechanisms of reactions like nucleophilic substitution and electrophilic addition.

8. Infrared Spectroscopy:
- Identification of functional groups in organic compounds based on their infrared spectra.
- Interpretation of spectra for different compounds, including fatty acids and alcohols.