Citric Acid, a white, crystalline acid with a taste like that of lemon juice. It is extracted from the juice of citrus fruits such as lemons, oranges, limes, and grapefruit. Commercial citric acid is prepared from lemons.

The acid is used in making medicines, particularly laxatives such as magnesium citrate. It is also used as a flavoring for soft drinks, in the manufacture of varnish remover, and in the dye industry. Citric acid is made synthetically by the fermentation of glucose. The acid combines with metals such as calcium and sodium to form salts known as citrates.

Chemical formula: HOC(CH2CO2H)2CO2H.