# Describe what is meant by a homologous series and state two characteristics that all members of the alkane homologous series share.

> Cambridge International IGCSE Chemistry (0620) — 11.1 Formulae, functional groups and terminology · Describe · 4 marks

## Mark scheme (4 marks)

1. A homologous series is a family/group of compounds with the same general formula (or same functional group)
2. Each successive member differs by CH₂ (one carbon and two hydrogen atoms)
3. All alkanes have the general formula CₙH₂ₙ₊₂
4. All alkanes contain only single (C–C and C–H) bonds / are saturated hydrocarbons

## Key terms

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

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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-what-is-meant-by-a-7a8a0544) · Published by Druglandscape Ltd.