Oxalic Acid  

It is colorless monoclinic flake or prism crystal or white powder. The oxalic acid produced by oxidation method has no odor, and the oxalic acid produced by synthesis method has taste. It was sublimated at 150-160 ℃. It can be weathered in high heat and dry air. 1g is soluble in 7 ml water, 2 ml boiling water, 2.5 ml ethanol, 1.8 mL boiling ethanol, 100 ml ether, 5.5 ml glycerol, but insoluble in benzene, chloroform and petroleum ether. It belongs to strong acid, the pH of 0.1 mol / L solution is 1.3. The relative density (water = 1) was 1.653. The melting point is 101-102 ℃ (187 ℃, without water). The median lethal dose (LD50) was 2000 mg / kg.

CAS No：144-62-7

Formula：H₂C₂O₄

Oxalic Acid used as Complexing agent, masking agent, precipitant and reducing agent. It is used for the determination of beryllium, calcium, chromium, gold, manganese, strontium and thorium. Sodium and other elements were examined by microcrystalline analysis. Calcium, magnesium, thorium and rare earth elements are precipitated. Calibrate the standard solution of potassium permanganate and cerium sulfate solution. bleaching agents. Dyeing aids. It can also be used to remove rust on clothes. In construction industry, oxalic acid should be applied to remove alkali before painting exterior wall coating.