Colorless and transparent crystal or powder. The crystal structure of two forms, namely α-(diamond) and β-type 

(monoclinic crystal). Odorless, Pickle. The proportion of 1.653, melting point 101 ℃, in dry air or when heated water is lost 

as a white powder. Oxalic acid is the organic acid of the two carboxyl acids, but also one of the organic acid in strong acid.

 And the role of concentrated sulfuric acid, have lost moisture, broken down into carbon dioxide and carbon monoxide. 

Oxalic acid also reducing, and oxidizing agents easily oxidized to carbon dioxide and water, and alkali and the role played 

in the generate oxalate.