Oxalate

Also known as: adipic acid; Xiu acid

English name: Oxalic acid; Ethanedioic acid; Dicarboxylic acid

Molecular Formula: HOOCCOOH; C2H2O4

Molecular Weight: 90.04

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

Melting point: α-type: 189.5 ℃, β-type: 182 ℃

Boiling point: [Molecular-dimensional model of] boiling point of 150 ℃ (sublimation).

Relative density: 1.653 (dihydrate), 1.9 (anhydrous). α-: 1.900, β-type: 1.895

Stability: 189.5 ℃ Decomposition

Dissolution conditions: soluble in ethanol. Soluble in water. Slightly soluble in ether. Not soluble in benzene and chloroform.

Other nature: oxalic acid at 100 ℃ start sublimation, 125 ℃, when the rapid sublimation, 157 ℃, when a large number of sublimation, and began to decompose.

With alkali reaction, can occur esterification, acyl halide, amide reaction. Reduction reaction can occur, heat decarboxylation reaction occurs. Anhydrous oxalic acid are hygroscopic. Oxalic acid with many metals to form water-soluble complexes.

Acid

Oxalic acid than in acetic acid (acetic acid) 10,000 times stronger is the organic acid in the acid. Its an ionization constant Ka1 = 5.9 × 10 ^ -2, two ionization constant Ka2 = 6.4 × 10 ^ -5. Perforating with acid. The occurrence with alkali and, enable the indicator color, to release carbon dioxide and carbonate role.

Toxic oxalic acid. On the skin, mucous membrane irritation and corrosive effects, easily through the skin, mucous membrane absorption of lead poisoning. Air maximum allowable concentration of 1m g/m3.