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Pyrophosphoric acid

Pyrophosphoric acid
IUPAC name phosphonooxyphosphonic
Other names diphosphoric acid
CAS number 2466-09-3
Molecular formula H4P2O7
Molar mass 177.98 g/mol
Melting point

61 °C

Boiling point


Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Pyrophosphoric acid, also known under the name diphosphoric acid, is a syrupy liquid or a needle-like crystalline solid. Pyrophosphoric acid is colorless, odorless, hygroscopic and is soluble in water, diethyl ether, and ethyl alcohol. It is the anhydride of phosphoric acid and is produced from phosphoric acid by dehydration. Pyrophosphoric acid slowly hydrolyzes in the presence of water into phosphoric acid.

2H3PO4 ⇌ H4P2O7 + H2O

Pyrophosphoric acid is a medium strong inorganic acid. The anion, the salts, and the esters of pyrophosphoric acid are called pyrophosphates.

See also

  • Sodium pyrophosphate
  • Calcium pyrophosphate dihydrate deposition disease
  • Dimethylallyl pyrophosphate
  • ATP


    This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Pyrophosphoric_acid". A list of authors is available in Wikipedia.
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