Phosphoric acid

Phosphoric acid is a weak mineral acid with the chemical formula H₃PO₄. Its main uses are in fertilizers and detergents, and in cleaning and rust-proofing agents. It is also used to acidify foods and beverages such as cola. Another specialized use is the provision of local anesthesia. Phosphoric acid is used in dentistry and orthodontics as an etching solution, to clean the surfaces of teeth where dental appliances or fillings will be placed. Phosphoric acid is prepared by adding sulphuric acid to calcium phosphate rock. In its anhydrous form the acid is a white solid. In aqueous solution, the acid releases three hydronium (H⁺) ions. The anion associated with phosphoric acid is called the phosphate ion, and is found pervasively in biology, especially in the compounds derived from phosphorylated sugars, such as DNA and RNA and adenosine triphosphate (e.g. ATP). Phosphoric acid is sometimes used in rat cleaning, animal testing, and is mixed with cow manure.