1. Oxalic acid can be used to remove rust. However, be careful when using oxalic acid on stainless steel has strong corrosiveness. High concentration of oxalic acid also corrodes hands easily. The acidic oxalate produced has high solubility, but has certain toxicity. When used, do not eat or drink. After skin contact with oxalic acid, it should be washed with water in time.

2. Chemical properties of oxalic acid. Oxalic acid began to sublimate at 100 C, rapidly at 125 C, and then began to decompose at 157 C. It can react with alkali, esterification, acyl halogenation and amidation can take place. Reduction can also occur and decarboxylation occurs when heated. Anhydrous oxalic acid has hygroscopicity. Oxalic acid can form water-soluble complexes with many metals.

3. Oxalic acid produces antibiotics, borneol and other drugs in daily life, as well as solvents, dye reductants and tanning agents for extracting rare metals.

4. Oxalic acid is used in chemical industry to produce pentaerythritol, cobalt oxalate, nickel oxalate and alkaline green. Steel, soil analysis kits, chemical reagents, etc. Fast dyes are used as color-developing auxiliaries. Bleaching agent for straw and wheat straw products (oxalic acid has reducibility).

5. Oxalic acid is widely used in other industries. Organic synthesis industry is mainly used to produce hydroquinone, pentaerythritol, cobalt oxalate, nickel oxalate, gallic acid and other chemical products. The plastic industry is used to produce polyvinyl chloride, amino plastics, urea-formaldehyde plastics, lacquer sheets, etc. The dyestuff industry is used to produce salt base green and so on. Printing and dyeing industry can replace acetic acid and be used as color auxiliaries and bleaching agents for pigment dyes. The pharmaceutical industry is used to manufacture aureomycin, oxytetracycline, tetracycline, streptomycin and ephedrine.