# A student is studying two organic compounds: ethanol and ethanoic acid. State the functional group present in each compound and explain why these two compounds belong to different homologous series.

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

## Mark scheme (4 marks)

1. Functional group of ethanol is the hydroxyl group / –OH
2. Functional group of ethanoic acid is the carboxyl group / –COOH
3. Each homologous series has the same functional group / a different functional group gives a different homologous series
4. Ethanol and ethanoic acid have different functional groups so they cannot belong to the same homologous series

## Key terms

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

## Related

- [Revision notes for Cambridge International IGCSE Chemistry (0620)](https://www.gradenine.co.uk/learn)
- [How to answer "State and Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-is-studying-two-organic-2c237b4e) · Published by Druglandscape Ltd.