Oxalic acid forms fine colourless crystals, readily soluble in water, with light nitrogen oxides-like odour. Oxalic acid dihydrate begins to dissociate at temperature over 30 0C. If heated quickly, it melts at 101.5 0C,anhydrous oxalic acid melts at 180 0C.

Applications: Purifying agent in pharmaceutical industry, special in antibiotic medication, such as Oxytetracycline , Chloramphenicol , etc;
Precipitating agent in Rare-earth mineral processing;
Bleaching agent in the textile activities, wood pulp bleaching;
Rust-remover for Metal treatment;
Grinding agent, such as Marble polishing;
Waste water treatment, removing calcium from water.