Explain why cracking is an important industrial process. In your answer, refer to both the feedstock used and the products formed.

Cracking is an important industrial process because it breaks down long‑chain hydrocarbons from crude oil into shorter molecules.
1. Long‑chain hydrocarbons are obtained from crude oil.
2. Cracking reduces these to smaller molecules.
3. Shorter‑chain fractions such as petrol and other fuels are in higher demand than the amounts produced by simple fractional distillation.
4. The main products of cracking are alkanes, which can be used directly as fuels.
5. Alkenes are also produced; these unsaturated hydrocarbons contain a C=C bond and can be used as monomers for addition polymerisation to make polymers.