Phosphoric acid

Absorption

Ortho phosphate is absorbed from, and to a limited extent secreted into, the gastrointestinal tract.

Toxicity

Man: LDLo, route unreported at 220mg/kg Rabbit: LD 50, Route: Skin, Reported dose: 2740 mg /kg, Effects: Behavioral : somnolence ( general depressed activity), Excitement Rat: LC50, Route: inhalation, Reported dose: >850 mg/m3/1h Rat: LD50, Route: oral, Reported dose: 1530 mg/kg, Effects: Kidney, ureter and bladder hematuria, Behavioral: somnolence (general depressed activity)

Description

Phosphoric acid was prepared first by Robert Boyle in 1694 by dissolving phosphorus pentoxide in water. Phosphoric acid is probably the most important compound of phosphorus. It is the second largest inorganic chemical by volume, after sulfuric acid, marketed in the United States.
The single most important application of Phosphoric acid is manufacturing phosphate salts for fertilizers. Such fertilizer phosphates include sodium, calcium, ammonium, and potassium phosphates. Other applications are in metal pickling and surface treatment for removal of metal oxides from metal surfaces; electropolishing of aluminum; as a bonding agent in various refractory products such as alumina and magnesia; as a catalyst in making nylon and gasoline; as a dehydrating agent; in fireproofing wood and fabrics; in lithographic engraving; in textile dyeing; in dental cement; in coagulating rubber latex; in purifying hydrogen peroxide; and as a laboratory reagent. Dilute solutions of phosphoric acid are used as additives to carbonated beverages for a pleasing sour taste. Also, dilute acid is used in refining sugar; as a nutrient; and as a buffering agent in preparing jam, jelly, and antibiotics. The commercial phosphoric acid is 85% (w/w) in strength.

Description

The most common form of phosphoric acid (H3PO4) is the 85% aqueous form. Pure anhydrous phosphoric acid is a white solid with a melting point of 42 C. Phosphoric acid has three pKa values covering a wide range (pKa's: 2.15, 7.20, 12.32). This is the reason why phosphoric acid solutions make a great choice as a buffer.

The Uses of Phosphoric acid

Phosphoric Acid is an acidulant that is an inorganic acid produced by burning phosphorus in an excess of air, producing phosphorus pentoxide which is dissolved in water to form orthophosphoric acid of varying concentrations. it is a strong acid which is soluble in water. the acid salts are termed phosphates. it is used as a flavoring acid in cola and root beer beverages to provide desirable acidity and sourness. it is used as a synergistic antioxidant in vegetable shorten- ings. in yeast manufacture, it is used to maintain the acidic ph and provide a source for phosphorus. it also functions as an acidulant in cheese. it is also termed orthophosphoric acid.

Indications

Phosphoric acid is used in dentistry and orthodontics as an etching solution, to clean and roughen the surfaces of teeth where dental appliances or fillings will be placed.

Background

Phosphoric Acid is a colorless, odorless phosphorus-containing inorganic acid. Phosphoric acid is a sequestering agent which binds many divalent cations, including Fe++, Cu++, Ca++, and Mg++.

What are the applications of Application

Phosphoric acid is an inorganic acid and phosphorylating agent

What are the applications of Application

Phosphoric acid solution is useful for HPLC

Pharmacokinetics

Transport of phosphate from the gut lumen is an active, energy-dependent process that is modified by several factors. ... Vitamin D stimulates phosphate absorption, an effect reported to precede its action on calcium ion transport.

Metabolism

Not Available