Oxalic acid

Oxalic Acid

Oxalic acid is an organic compound with the formula C2H2O4. It is a colorless crystalline solid that forms a colorless solution in water. Its condensed formula is HOOCCOOH, reflecting its classification as the simplest dicarboxylic acid.

Properties

Oxalic acid is a strong organic acid, and is readily available in various plants and vegetables. It is also produced in the body by metabolism of glyoxylic acid or ascorbic acid. It is not metabolized but excreted in the urine. It is classified as a strong acid due to the complete ionization of its two hydroxyl groups in solution.

Production

Oxalic acid is produced by the oxidation of carbohydrates or glucose using nitric acid or air in the presence of vanadium pentoxide. A significant amount of the vanadium pentoxide is converted into vanadyl oxalate, a side product which can be converted back into the catalyst.

Uses

Oxalic acid has a variety of uses, including as a cleaning agent, particularly for the removal of rust. It is used in many commercial products that are designed to clean things from metals to decks. In the pharmaceutical industry, it is used as a precipitating agent. It is also used in the dyeing processes.

Health Effects

Ingestion of oxalic acid or prolonged skin contact can be dangerous. It can cause kidney damage, as the acid or its salts can form tiny sharp crystals in the kidney tubules, damaging them and causing kidney disease. It can also cause digestive problems and affect calcium absorption in the body.

See Also

• Dicarboxylic acid
• Organic acid
• Vanadium pentoxide
• Glyoxylic acid
• Ascorbic acid