A pure substance is a substance that has a definite and uniform composition throughout. Acetic acid is a chemical compound with the formula CH3COOH. It is a colorless liquid with a strong, pungent odor. Acetic acid is the main component of vinegar.

Acetic acid can be produced by the fermentation of ethanol by acetic acid bacteria. It can also be produced by the oxidation of acetaldehyde or by the reaction of carbon monoxide and methanol.

Acetic acid is used in a variety of applications, including:

* As a food preservative

* As a cleaning agent

* As a solvent

* As a chemical intermediate

Acetic acid is a pure substance because it has a definite and uniform composition throughout. It is a chemical compound with a specific molecular formula and structure.