4(b) Crude oil
Pearson Edexcel International GCSE Chemistry · 4CH1
Paper 2 | Whole paper: All content including bold C statements
A mixture separated by boiling point, the fractions it yields, and the cracking that fixes the mismatch between supply and demand.
Specification coverage
Topic 4 Organic chemistry (b) Crude oil — statements 4.5–4.13C (includes bold C statements assessed on Paper 2 only)
Assessment objectives: AO1, AO2. Suggested learning time: 70 minutes.
Required knowledge
- Crude oil as a mixture of hydrocarbons and its separation by fractional distillation
- The names and uses of the main fractions
- The trend in properties down the fractionating column
- Complete and incomplete combustion, and the problems caused by the products
- Cracking: what it produces and why it is necessary
- Bold C statements: cracking conditions and equations in greater depth
Required skills
- Explain fractional distillation in terms of boiling point and intermolecular forces
- Write equations for combustion and for cracking
- Explain the environmental problems of each combustion product
How it is examined
- Multiple-choice and short-answer recall
- Application of the content to an unfamiliar context
- Extended open-response, marked on the quality of a connected explanation
Common mistakes
- Saying fractional distillation separates by 'weight'. It separates by boiling point, which depends on chain length and intermolecular forces.
- Confusing the products of complete and incomplete combustion. Incomplete combustion produces carbon monoxide and carbon.
- Saying cracking produces 'smaller molecules' without naming an alkane and an alkene as products.