Explain, with reasons, the boiling points and the solubility in water of alcohols and phenols.

1. 1 · State the key idea. The -OH group forms hydrogen bonds.
2. 2 · Boiling point. Intermolecular hydrogen bonds hold the molecules together, so more energy is needed: ethanol 351 K, methoxymethane 248 K, propane 231 K.
3. 3 · Trends. Boiling point rises with more carbon atoms and falls with branching (less surface area).
4. 4 · Solubility. The -OH group hydrogen bonds with water, so lower alcohols are miscible; the hydrophobic alkyl part lowers solubility as it grows.
5. 5 · Link to real life. Sanitisers are alcohol-water mixtures because the two mix completely.
6. 6 · Close in one line. So one hydrogen bond explains both the high boiling point and the solubility.

Scoring tip: Name the type of force (hydrogen bond, van der Waals) in every reason you give.