Oxalic acid is an organic compound with the formula H2C2O4. This colourless solid is a dicarboxylic acid. In terms of acid strength, it is about 3,000 times stronger than acetic acid. Oxalic acid is a reducing agent and itsconjugate base, known as oxalate(C2O42−), is a chelating agent for metal cations. Typically oxalic acid occurs as the dihydrate with the formula C2O4H2·2H2O.
