benzoico

Benzoic acid, also known as benzoic acid, is a simple aromatic carboxylic acid with the chemical formula C7H6O2. It consists of a benzene ring bearing a single carboxyl group (CO2H). This structure gives benzoic acid its characteristic acidity and reactivity, making it a versatile starting material in organic synthesis.

In terms of properties, benzoic acid is a colorless crystalline solid with a melting point of about 122.4 °C. It is more soluble in organic solvents than in water, and its salts are generally more water-soluble. The pKa of benzoic acid in water is around 4.2, reflecting its behavior as a weak acid.

Industrial production of benzoic acid is mainly by the catalytic oxidation of toluene with air, using metal catalysts such as cobalt or manganese. It can also be obtained by oxidation of benzyl compounds or by hydrolysis of certain benzoate esters. The compound serves as a precursor to many derivatives, including benzoyl chloride and various esters used in fragrances, dyes, and pharmaceutical intermediates.

Benzoic acid is widely used as a preservative in foods and cosmetics in the form of benzoates, notably sodium benzoate and potassium benzoate (E211 and E212). It also functions as an intermediate in organic synthesis and is employed in the production of plastics, resins, and certain flavors and fragrances. Natural sources include trace amounts in various fruits and plant-derived materials.

Safety and regulation: benzoic acid and its salts are generally recognized as safe at regulated concentrations. They may cause irritation at higher exposures and can provoke allergic reactions in sensitive individuals.