# Describe what happens during the incomplete combustion of an alkane, and explain why the products formed are harmful.

> Pearson Edexcel International GCSE Chemistry (4CH1) — 4.3 Alkanes · Describe · 4 marks

> Alkanes are the most common hydrocarbons found in crude oil and are widely used as fuels. When alkanes burn, the products formed depend on the amount of oxygen available.

## Mark scheme (4 marks)

1. Incomplete combustion occurs when there is insufficient oxygen
2. Carbon monoxide is produced during incomplete combustion
3. Carbon monoxide is toxic / harmful to humans
4. Carbon particulates are also produced and cause global dimming / health problems

## Key terms

- [incomplete combustion](https://www.gradenine.co.uk/glossary/incomplete-combustion)
- [alkane](https://www.gradenine.co.uk/glossary/alkane)

## Related

- [Revision notes for Pearson Edexcel International GCSE Chemistry (4CH1)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-what-happens-during-the-incomplete-53d9d2f2) · Published by Druglandscape Ltd.