09-11-2021-2043 - Phosphoric acid, also known as orthophosphoric acid or phosphoric(V) acid

 Phosphoric acid, also known as orthophosphoric acid or phosphoric(V) acid, is a weak acid with the chemical formula H

3PO
4. The pure compound is a colorless solid.

All three hydrogens are acidic to varying degrees and can be lost from the moleculeas H⁺ ions (protons). When all three H⁺ ions are removed, the result is an orthophosphate ion PO₄³⁻, commonly called "phosphate". Removal of one or two protons gives dihydrogen phosphate ion H
2PO−
4, and the hydrogen phosphate ion HPO2−
4, respectively. Orthophosphoric acid also forms esters, called organophosphates.^[15]

Phosphoric acid is commonly encountered in chemical laboratories as an 85% aqueous solution, which is a colourless, odourless, and non-volatile syrupy liquid. Although phosphoric acid does not meet the strict definition of a strong acid, the 85% solution can still severely irritate the skin and damage the eyes.

The name "orthophosphoric acid" can be used to distinguish this specific acid from other "phosphoric acids", such as pyrophosphoric acid. Nevertheless, the term "phosphoric acid" often means this specific compound; and that is the current IUPAC nomenclature.

This article is about orthophosphoric acid. For other acids commonly called "phosphoric acid", see Phosphoric acids and phosphates.

Not to be confused with Phosphorous acid.

https://en.wikipedia.org/wiki/Phosphoric_acid