The structural formula of benzoic acid is C6H5COOH. Also known as benzoic acid, it is odorless or has a slight benzoin smell. It is widely used as a food preservative. It is naturally found in cranberries, prunes, cinnamon, and cloves. It is an aromatic acid and can also be added as a spice.

Benzoic acid is a weak acid, stronger than fatty acids. They have similar chemical properties and can form salts, esters, acid halides, amides, acid anhydrides, etc., and are not easily oxidized. Electrophilic substitution reaction can occur on the benzene ring of benzoic acid, mainly obtaining meta-substitution products.

It is an acid with the simplest molecular composition among aromatic acids. Benzoic acid is a white needle-shaped crystal with a melting point of 122.4 degrees Celsius. It sublimes easily, is slightly soluble in water, is easily soluble in ethanol and ether, and is slightly more acidic than acetic acid.

Uses and functions of benzoic acid

Benzoic acid widely exists in nature in the form of free acid, ester or its derivatives. Benzoic acid is often used as a drug or preservative. It has the effect of inhibiting the growth of fungi, bacteria, and mold. When used medicinally, it is usually applied to the skin to treat skin diseases such as ringworm. Used in synthetic fibers, resins, coatings, rubber, and tobacco industries.

Originally, benzoic acid is produced by carbonization of benzoin gum or hydrolysis of alkaline water. It can also be produced by hydrolysis of hippuric acid. Industrially, benzoic acid is produced by air oxidation of toluene in the presence of catalysts such as cobalt and manganese; or it is produced by hydrolysis and decarboxylation of phthalic anhydride. Benzoic acid and its sodium salt can be used as bacteriostatic agents in latex, toothpaste, jam or other foods, and can also be used as mordants for dyeing and printing.