Chemistry 9701/21 May June 2017 | Cambridge AS Level Past Papers With Mark Scheme

### 1. Combustion and Empirical Formula Calculation:
- Determining the empirical formula, molecular formula, and mass of an alcohol based on combustion data, including volume measurements and reaction equations.

### 2. Structure and Bonding:
- Understanding the bonding and lattice structure in different substances like copper, ice, silicon(IV) oxide, iodine, and sodium chloride, and drawing diagrams to represent hydrogen bonding in water.

### 3. Periodic Trends and Group 2 Reactions:
- Identifying elements based on their properties and reactions, such as their ability to form amphoteric oxides, their first ionization energy, and how magnesium and calcium react with oxygen and water.
- Writing equations for thermal decomposition reactions.

### 4. Organic Chemistry (Functional Groups and Reactions):
- Exploring the structure and functional groups in isomers, reactions of alkenes with acidified manganese(VII) and bromine, and understanding reactions involving hydrogen cyanide and 2,4-DNPH.
- Drawing reaction mechanisms, understanding optical isomerism, and identifying products formed in various reactions.

### 5. Thermodynamics and Enthalpy:
- Using the provided enthalpy data to calculate enthalpy changes for reactions like the formation of phosphorus(III) chloride.