Alcohols are very versatile compounds, and they undergo a variety of important reactions. The common reactions of alcohols include:
- Combustion – Alcohols burn in oxygen to produce carbon dioxide and water, releasing energy.
- Dehydration – In the presence of concentrated sulfuric acid or phosphoric acid and heat, alcohols lose a water molecule to form an alkene.
- Oxidation –
- Primary alcohols can be oxidized to aldehydes and then further to carboxylic acids.
- Secondary alcohols are oxidized to ketones.
- Tertiary alcohols generally resist oxidation under normal conditions.
- Esterification – Alcohols react with carboxylic acids in the presence of an acid catalyst to form esters, which often have fruity smells.
- Substitution reactions – The hydroxyl group of alcohols can be replaced by halogens when treated with halogenating agents, forming alkyl halides.
- Reaction with sodium – Alcohols react with sodium metal to produce hydrogen gas and sodium alkoxides.
- Formation of ethers – Under certain conditions, two alcohol molecules can combine (dehydration) to form ethers.