Lactic acid


Lactic acid (IUPAC systematic name: 2-hydroxypropanoic acid), also known as milk acid, is a chemical compound that plays a role in several biochemical processes. It was first isolated in 1780 by a Swedish chemist, Carl Wilhelm Scheele, and is a carboxylic acid with a chemical formula of C<sub>3</sub>H<sub>6</sub>O<sub>3</sub>. It has a hydroxyl group adjacent to the carboxyl group, making it an alpha hydroxy acid (AHA). In solution, it can lose a proton from the acidic group, producing the lactate ion CH<sub>3</sub>CH(OH)COO<sup>−</sup>. It is miscible with water or ethanol, and is hygroscopic.