# Outline how the functional groups present in ethanoic acid and ethylamine allow each compound to be classified as belonging to a homologous series, and identify one chemical property that distinguishes them from each other.

> IB DP Chemistry Standard Level (2023 syllabus) — S3.2 Functional groups: classification of organic compounds · Outline · 4 marks

## Mark scheme (4 marks)

1. Ethanoic acid contains a carboxyl (–COOH) functional group, which classifies it as a carboxylic acid.
2. Ethylamine contains an amino (–NH₂) functional group, which classifies it as an amine.
3. Ethanoic acid is acidic / donates a proton (H⁺), whereas ethylamine is basic / accepts a proton (H⁺).
4. Ethanoic acid reacts with ethylamine (or other bases/carbonates) but ethylamine does not react in the same way / they react together to form a salt (ethylammonium ethanoate).

## 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 IB DP Chemistry Standard Level (2023 syllabus)](https://www.gradenine.co.uk/learn)
- [How to answer "Outline" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/outline-how-the-functional-groups-present-38781049) · Published by Druglandscape Ltd.