الوصف

Name: oxalic acid
Also known as: oxalic acid; repair acid
English name: Oxalic acid; Ethanedioic acid; Dicarboxylic acid
Molecular formula: H2C2O4
Simple structure: HOOCCOOH;
Molecular Weight: *0.*4
Structure: see right
Functional group:-COOH (carboxyl)
Ions in solution components: C2O4 2 - (oxalate ion), H (hydrogen ions), HC2O*-(oxalic acid hydrogen ion)
CAS No. :*******7; ********6 (dihydrate)
Properties: Colorless transparent crystal or powder. The crystal structure of two forms, namely α-(diamond) and β-type (monoclinic crystal form). Odorless, Pickle.
Melting point: α-type: **9.5 ℃, β-type: **2 ℃
Boiling point: [Molecular-dimensional model of] the boiling point of **0 ℃ (sublimation).
Relative density: 1.**3 (dihydrate), 1.9 (anhydrous). α-type: 1.**0, β-type: 1.**5
Refractive index: 1.**0
Stability: **9.5 ℃ Decomposition
Dissolved: soluble in ethanol. Soluble in water. Slightly soluble in ether. Not soluble in benzene and chloroform.
Other properties: sublimation of oxalic acid started at **0 ℃, **5 ℃ when the rapid sublimation, **7 ℃ when the large number of sublimation, and began to decompose.
With alkali reaction, can occur esterification, acyl halide, amide reaction. Reduction reaction can occur, heat decarboxylation occurred. Anhydrous oxalic acid are hygroscopic. The formation of oxalic acid with many water-soluble metal complexes.
Acid
Oxalic acid than acetic acid (acetic acid), *0,**0 times stronger, is the organic acid in the acid. The level of ionization constant Ka1 = 5.9 × *0 ^ *2, ionization constant Ka2 = 6.4 × *0 ^ *5. Continuity with the acid. Occurrence with alkali and, enable indicator color, to release carbon dioxide and the role of carbonate.