Acetic acid, or ethanoic acid, (CHCOOH) is a carboxylic acid, which is the main compound of vinegar, other than water. It tastes and smells sour; it has no color. Its melting point is 16.5 °C(61.6 °F) and boiling point is 118.1 °C(244.5 °F). It has a pH of 2.4.