Crude oil is a complex mixture of hydrocarbons that can be separated into fractions by fractional distillation. The table below shows the boiling point ranges for four of these fractions:
| Fraction | Boiling point range (∘C^\circ\text{C}∘C) |
|---|---|
| P | 30–80 |
| Q | 80–120 |
| R | 120–180 |
| S | 180–240 |
Identify the fraction that is the most viscous at room temperature.
Identify the fraction that is the most volatile (easiest to evaporate).
Fraction S contains decane, which is a straight-chain alkane containing ten carbon atoms.
Determine the molecular formula of decane.
Give the general formula of the homologous series that includes decane.
Pentadecane, C15H32\text{C}_{15}\text{H}_{32}C15H32, is a long-chain alkane. It can be cracked to produce nonane, C9H20\text{C}_9\text{H}_{20}C9H20, and two molecules of the same alkene. Write a balanced chemical equation for this cracking reaction.
State two conditions used in industry for catalytic cracking.
19 exam-style questions on Edexcel IGCSE Chemistry Crude oil. Each one has a worked solution and a mark scheme showing where the marks go.