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.
Levulinic acid Levulinic acid Levulinic acid, or 4-oxopentanoic acid, is an organic compound with the formula CHC(O)CHCHCOH. It is classified as a keto acid. This white crystalline solid is soluble in water and polar organic solvents. It is derived from degradation of cellulose and is a potential precursor to biofuels, such as ethyl levulinate. In 1840 the Dutch professor Gerardus Johannes Mulder mentioned levulinic acid for the first time. He synthesized it by heating fructose with hydrochloric acid. The former term “levulose” for fructose gave levulinic acid its name. Although levulinic acid has been well known since the 1870s, it has never