Acetic acid Acetic acid Acetic acid , systematically named ethanoic acid , is a colourless liquid organic compound with the chemical formula CHCOOH (also written as CHCOH or CHO). When undiluted, it is sometimes called "glacial acetic acid". Vinegar is no less than 4% 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
Maleic acid Maleic acid Maleic acid or "cis"-butenedioic acid is an organic compound that is a dicarboxylic acid, a molecule with two carboxyl groups. Its chemical formula is HOCCH=CHCOH. Maleic acid is the "cis"-isomer of butenedioic acid, whereas fumaric acid is the "trans"-isomer. It is mainly used as a precursor to fumaric acid, and relative to its parent maleic anhydride, maleic acid has few applications. Maleic acid is a less stable molecule than fumaric acid. The difference in "heat of combustion" is 22.7 kJ/mole. The heat of combustion is -1355 kJ/mole. Maleic acid is more soluble in water than fumaric acid. The