# Methanol, ethanol and propan-1-ol are the first three members of the alcohol homologous series. Describe the physical properties of these three alcohols and explain how and why these properties change as the carbon chain length increases.

> Eduqas A-Level Chemistry — 4.3 Alcohols and phenols · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. All three alcohols are liquids at room temperature (or have relatively low boiling points)
2. All three alcohols are miscible with water / dissolve completely in water
3. Boiling point increases as the carbon chain length increases (from methanol to propan-1-ol)
4. Larger molecules have stronger intermolecular forces / more energy needed to separate the molecules
5. Solubility in water decreases as chain length increases / propan-1-ol is less soluble than methanol

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level Chemistry](https://www.gradenine.co.uk/learn)
- [How to answer "Describe 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/methanol-ethanol-and-propan-1-ol-are-the-8796ddaa) · Published by Druglandscape Ltd.