<Tr> <Td_colspan="2"> Infobox references </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> </Tr> <P> Acetic acid / əˈsiːtɪk /, systematically named ethanoic acid / ˌɛθəˈnoʊɪk /, is a colourless liquid organic compound with the chemical formula CH COOH (also written as CH CO H or C H O). When undiluted, it is sometimes called glacial acetic acid . Vinegar is roughly 3--9% acetic acid by volume, making acetic acid the main component of vinegar apart from water . Acetic acid has a distinctive sour taste and pungent smell . In addition to household vinegar, it is mainly produced as a precursor to polyvinyl acetate and cellulose acetate . It is classified as a weak acid since it only partially dissociates in solution, but concentrated acetic acid is corrosive and can attack the skin . </P> <P> Acetic acid is the second simplest carboxylic acid (after formic acid). It consists of a methyl group attached to a carboxyl group . It is an important chemical reagent and industrial chemical, used primarily in the production of cellulose acetate for photographic film, polyvinyl acetate for wood glue, and synthetic fibres and fabrics . In households, diluted acetic acid is often used in descaling agents . In the food industry, acetic acid is controlled by the food additive code E260 as an acidity regulator and as a condiment . In biochemistry, the acetyl group, derived from acetic acid, is fundamental to all forms of life . When bound to coenzyme A, it is central to the metabolism of carbohydrates and fats . </P>

What is the chemical formula for acetic acid