Oxalic acid Oxalic acid Oxalic acid is an organic compound with the formula CHO. It is a colorless crystalline solid that forms a colorless solution in water. Its condensed formula is HOOCCOOH, reflecting its classification as the simplest dicarboxylic acid. Its acid strength is much greater than that of acetic acid. Oxalic acid is a reducing agent and its conjugate base, known as oxalate (), is a chelating agent for metal cations. Typically, oxalic acid occurs as the dihydrate with the formula CHO·2HO. It occurs naturally in many foods, but excessive ingestion of oxalic acid or prolonged skin contact can be dangerous.
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