Oxalic acid is an organic acid with the IUPAC name ethanedioic acid and formulaHO2CCO2H. It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water.
Oxalic acid's main applications include cleaning or bleaching, especially for the removal of rust (iron complexing agent). Its utility in rust removal agents is due to its forming a stable, water-soluble salt with ferric iron, ferrioxalate ion.