Fosforan

Fosforan is the term used for the phosphate group or phosphate anion derived from phosphoric acid (H3PO4). In common usage, it refers to orthophosphate (PO4^3−) and related phosphate species such as dihydrogen phosphate (H2PO4−) and hydrogen phosphate (HPO4^2−). The phosphate ion has a tetrahedral geometry around phosphorus; resonance distributes oxygens with one P=O double bond and three P–O bonds.

In solution, acid-base chemistry yields several species depending on pH; pKa values: pKa1 ~2.15 (H3PO4 → H2PO4−), pKa2 ~7.20 (H2PO4− → HPO4^2−), pKa3 ~12.35 (HPO4^2− → PO4^3−).

Occurrence and role: Phosphates are abundant in minerals (apatite), soils, and organisms. In biology, phosphate diesters form the backbone of DNA and RNA; adenosine triphosphate (ATP) stores energy via phosphoanhydride bonds. In geology and materials, phosphates occur as calcium phosphate minerals in bones and teeth.

Production and applications: In industry, phosphate rock is processed to phosphoric acid, which is neutralized to yield mono-, di-, and calcium phosphates used as fertilizers and food additives. Phosphates function as buffering agents, sequestrants in detergents and water treatment, and corrosion inhibitors. Organophosphates include pesticides and flame retardants, though regulation and safety concerns apply.

Environmental and safety notes: Excess phosphate discharge promotes eutrophication in waterways. In general, phosphates are handled with standard chemical safety practices; specific organophosphates may pose different risks.

See also: phosphate, orthophosphate, polyphosphate, ATP, DNA, RNA.