what is oxalic acid
Oxalic acid is an organic compound with the formula H 2 C 2 O 4 (also written as HOOCCOOH). It is a colorless crystalline solid that forms a colorless solution in water.It is classified as a dicarboxylic acid.ypically, oxalic acid occurs as the dihydrate with the formula H 2 C 2 O 4 Â·2H 2 O. Excessive ingestion of oxalic acid or prolonged skin contact can be dangerous.