Acetic acid acid solutions: Concentrated acetic acid can be ignited only with difficulty at standard temperature and pressure, but becomes a flammable risk in temperatures greater than , and can form explosive mixtures with air at higher temperatures (explosive limits: 5.4–16%). 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
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