# Alkanes belong to a homologous series. State the general formula of alkanes and describe three features that are shared by all members of a homologous series.

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

## Mark scheme (4 marks)

1. General formula of alkanes is CₙH₂ₙ₊₂
2. All members of a homologous series have the same functional group
3. All members have similar chemical properties
4. Each successive member differs by CH₂ (one carbon and two hydrogen atoms) / members differ by a constant unit of CH₂

## Key terms

- [homologous series](https://www.gradenine.co.uk/glossary/homologous-series)
- [general formula](https://www.gradenine.co.uk/glossary/general-formula)

## Related

- [Revision notes for Pearson Edexcel International GCSE Chemistry (4CH1)](https://www.gradenine.co.uk/learn)
- [How to answer "State and Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/alkanes-belong-to-a-homologous-series-e5ef13f0) · Published by Druglandscape Ltd.