At an oil refinery, some large alkane molecules are broken down by cracking.
Decane can be cracked to form octane and one other product.
C10H22→C8H18+\mathrm{C_{10}H_{22}} \rightarrow \mathrm{C_{8}H_{18}} + C10H22→C8H18+ ........
State two conditions used for cracking.
Give the formula of the other product in this reaction.
Name the homologous series that the other product belongs to.
Describe a test to show that the other product is unsaturated. Give the result.
The table shows the percentage of some fractions in crude oil (supply) and the percentage needed by customers (demand).
| Fraction | Supply / % | Demand / % |
|---|---|---|
| gases | 2 | 4 |
| petrol | 16 | 27 |
| kerosene | 13 | 8 |
| diesel oil | 19 | 23 |
| fuel oil and bitumen | 50 | 38 |
Explain, using the data, why cracking is necessary.
37 exam-style questions on Edexcel GCSE Chemistry 9.1 Fuels, covering 9.1.1 Hydrocarbons and crude oil, 9.1.2 Fractional distillation of crude oil and its fractions, 9.1.3 The alkanes as a homologous series, 9.1.4 Complete and incomplete combustion, 9.1.5 Pollutants from burning fuels, 9.1.6 Hydrogen as a fuel and non-renewable fossil fuels, and 9.1.7 Cracking of larger alkanes. Each one has a worked solution and a mark scheme showing where the marks go.