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.
Dihydroxymalonic acid heated with urea to 100 °C, it forms allantoin. By continued boiling of its aqueous solution it is decomposed into carbon dioxide and glyoxylic acid. Dihydroxymalonic acid Dihydroxymalonic acid is an organic compound with formula CHO or HO-(C=O)-C(OH)-(C=O)-OH, found in some plants such as alfalfa and in beet molasses. The compound may also be called dihydroxymesoxalic acid, dihydroxypropanedioic acid. It can be viewed as a hydrate derivative of mesoxalic acid, and indeed it is often called mesoxalic acid monohydrate and other silmilar names. This compound is unusual in containing stable geminal hydroxy groups. Dihydroxymalonic acid is a water-soluble white solid.