Acetic

Acetic is an adjective used in chemistry and related fields to refer to acetic acid and its derivatives. The term derives from Latin acetum, meaning vinegar. In many contexts, acetic describes compounds that contain the acetic acid moiety, CH3CO2H, or the acetate ion, CH3COO−.

Acetic acid, also called ethanoic acid, is a colorless, pungent liquid. It is a weak carboxylic acid with the formula C2H4O2. At temperatures below 16.6 °C it solidifies as glacial acetic acid. It is miscible with water and many organic solvents. The conjugate base forms acetate salts, which are widely used in chemistry and biochemistry. The vapor is irritating, and concentrated solutions are caustic.

Production typically occurs in two broad ways. Traditionally, acetic acid is produced via fermentation of ethanol by acetic acid bacteria in the presence of oxygen, as in vinegar. Industrially, most acetic acid is produced by carbonylation of methanol (the Monsanto and Cativa processes), followed by purification. An older chemical route involves the selective oxidation of acetaldehyde to acetic acid.

Uses of acetic acid and its derivatives are extensive. In food, acetic acid is the active component of vinegar and serves as a preservative and flavoring agent. In chemistry, acetate salts and esters are widely used; ethyl acetate is a common solvent. Acetic acid is also dehydrated to form acetic anhydride, a important acetylating agent for preparing acetylated products and polymers.

Safety and handling focus on its corrosive nature. Concentrated acetic acid can cause severe burns; vapors and splashes should be avoided with appropriate protective equipment. Waste and emissions are managed to minimize environmental impact.