Oxalic acid isan organiccompound with the formula H2C2O4.It is a colorless crystalline solid that dissolves in water to givecolorless solutions. It is classified as a dicarboxylicacid. In terms of acid strength, it is much strongerthan acetic acid.Oxalic acid is a reducingagent and its conjugatebase, known as oxalate (C2O42−),is a chelatingagent for metal cations. Typically, oxalic acidoccurs as the dihydratewiththe formulaH2C2O4·2H2O.Ingestion of oxalic acid through skin contact or orally isdangerous.