Fosforihappo

Fosforihappo, known in English as phosphoric acid, is a colorless, odorless inorganic acid with the chemical formula H3PO4. It is a triprotic acid; in aqueous solution it dissociates stepwise to form dihydrogen phosphate (H2PO4−), hydrogen phosphate (HPO4^2−) and phosphate (PO4^3−) species, with approximate pKa values of 2.15, 7.20 and 12.35. It is soluble in water and forms clear, mildly corrosive solutions.

Production and supply: The dominant industrial route is the reaction of phosphate rock with sulfuric acid to produce phosphoric acid and calcium sulfate as a byproduct (phosphogypsum). The phosphoric acid is then concentrated by evaporation for use in fertilizers or purified for food and other applications. In fertilizer production, phosphoric acid is neutralized with ammonia to form ammonium phosphate fertilizers such as monoammonium phosphate (MAP) and diammonium phosphate (DAP).

Applications: In agriculture, phosphoric acid provides a key source of phosphorus for crop nutrition and is a component of many phosphate fertilizers. In the food and beverage industry, it is used as an acidulant and acidity regulator (often labeled as E338). It also serves as a cleaning and rust-removing agent, and as a precursor for phosphate esters used in detergents, surfactants and various industrial chemicals.

Safety and handling: Phosphoric acid is corrosive to skin and eyes, and concentrated solutions can cause severe chemical burns. It should be handled with appropriate personal protective equipment, stored in corrosion-resistant containers, and kept away from bases and strong oxidizers. In case of contact, skin or eye exposure should be flushed with plenty of water; spills require neutralization and proper disposal following local regulations. Environmental note: as a source of phosphate, excessive discharge can contribute to aquatic eutrophication.