ethanoic acid

One of the simplest carboxylic acids (fatty acids). In the pure state it is a colourless liquid with an unpleasant pungent odour; it solidifies to an icelike mass of crystals at 16.7°C/62.4°F, and hence is often called glacial ethanoic acid. In a dilute form, mixed with water, it is the acid found in vinegar. Vinegar contains 5% or more ethanoic acid, produced by fermentation.

Ethanoic acid is produced by the oxidation of ethanol. It belongs to a homologous series, or family, of organic compounds. Some other members of the series are methanoic acid, propanoic acid, and butanoic acid. They are all weak acids.

Cellulose (derived from wood or other sources) may be treated with ethanoic acid to produce a cellulose ethanoate (acetate) solution, which can be used to make plastic items by injection moulding or extruded to form synthetic textile fibres.