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

> AQA A-Level Chemistry (7405) — 3.3.7 Optical isomerism (A-Level only) · Explain · 5 marks

## Mark scheme (5 marks)

1. Long-chain hydrocarbons (from crude oil) are broken down into smaller molecules
2. There is greater demand for shorter-chain fractions (e.g. petrol / fuels) than is obtained directly from fractional distillation of crude oil
3. The products of cracking include alkanes, which can be used as fuels
4. Alkenes are also produced, which are unsaturated hydrocarbons containing a carbon–carbon double bond
5. Alkenes can be used as monomers for addition polymerisation to make polymers

## Key terms

- [cracking](https://www.gradenine.co.uk/glossary/cracking)

## Related

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-cracking-is-an-important-0226f2d6) · Published by Druglandscape Ltd.