# Distinguish between the structures and chemical properties of a primary alcohol and a carboxylic acid, with reference to their functional groups.

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

## Mark scheme (4 marks)

1. A primary alcohol contains the hydroxyl functional group (–OH) attached to a carbon bonded to at most one other carbon, whereas a carboxylic acid contains the carboxyl functional group (–COOH), which consists of a carbonyl (C=O) and a hydroxyl (–OH) on the same carbon.
2. Carboxylic acids are acidic and can donate a proton (H⁺) from the –COOH group to form a carboxylate ion, whereas primary alcohols are not acidic under normal conditions and do not readily donate a proton.
3. Primary alcohols can be oxidised (e.g. by acidified potassium dichromate) first to an aldehyde and then to a carboxylic acid, whereas carboxylic acids resist further oxidation under normal laboratory conditions.
4. Carboxylic acids undergo condensation reactions with alcohols (esterification) to form esters and water, a reaction not possible between two alcohol molecules under the same conditions.

## Key terms

- [primary alcohol](https://www.gradenine.co.uk/glossary/primary-alcohol)
- [carboxylic acid](https://www.gradenine.co.uk/glossary/carboxylic-acid)

## Related

- [Revision notes for IB DP Chemistry Standard Level (2023 syllabus)](https://www.gradenine.co.uk/learn)
- [How to answer "Distinguish" 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/distinguish-between-the-structures-and-chemical-01bcb0b8) · Published by Druglandscape Ltd.