Acetic acid

Acetic acid occurs in vinegar. It is producedin the destructive distillation of wood. Itfinds extensive application in the chemicalindustry. It is used in the manufacture ofcellulose acetate, acetate rayon, and variousacetate and acetyl compounds; as a solventfor gums, oils, and resins; as a food preservative in printing and dyeing; and in organicsynthesis.
Acetic acid, CH3COOH, is a colorless, volatile liquid at ambient temperatures. The pure compound, glacial acetic acid, owes its name to its ice-like crystalline appearance at 15.6°C. As generally supplied, acetic acid is a 6 N aqueous solution (about 36%) or a 1 N solution (about 6%). These or other dilutions are used in adding appropriate amounts of acetic acid to foods. Acetic acid is the characteristic acid of vinegar, its concentration ranging from 3.5 to 5.6%. Acetic acid and acetates are present in most plants and animal tissues in small but detectable amounts. They are normal metabolic intermediates, are produced by such bacterial species as Acetobacter and can be synthesized completely from carbon dioxide by such microorganisms as Clostridium thermoaceticum. The rat forms acetate at the rate of 1% of its body weight per day.