Pyrophosphoric acid

Pyrophosphoric acid
IUPAC name Diphosphoric acid μ-oxido-bis(dihydroxidooxidophosphorus)
Other names Diphosphoric acid
Identifiers
CAS number	2466-09-3 Y
PubChem	1023
ChemSpider	996 Y
UNII	4E862E7GRQ Y
ChEBI	CHEBI:29888 Y
ChEMBL	CHEMBL1160571 Y
Jmol-3D images	Image 1
SMILES O=P(O)(O)OP(=O)(O)O
InChI InChI=1S/H4O7P2/c1-8(2,3)7-9(4,5)6/h(H2,1,2,3)(H2,4,5,6) Y Key: XPPKVPWEQAFLFU-UHFFFAOYSA-N Y InChI=1/H4O7P2/c1-8(2,3)7-9(4,5)6/h(H2,1,2,3)(H2,4,5,6) Key: XPPKVPWEQAFLFU-UHFFFAOYAX
Properties
Molecular formula	H4P2O7
Molar mass	177.98 g/mol
Melting point	71.5 °C
Solubility in water	Extremely soluble
Solubility	Very soluble in alcohol, ether
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Pyrophosphoric acid, also known under the name diphosphoric acid, is colorless, odorless, hygroscopic and is soluble in water, diethyl ether, and ethyl alcohol. It is produced from phosphoric acid by dehydration. Pyrophosphoric acid slowly hydrolyzes in the presence of water into phosphoric acid.

H₄P₂O₇ + H₂O 2H₃PO₄

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

While pyrophosporic acid is corrosive, it is not known to be otherwise toxic.

See also

• Sodium pyrophosphate
• Calcium pyrophosphate dihydrate deposition disease
• Dimethylallyl pyrophosphate
• ADP
• ATP
• Ortho acids
• triphosphoric acid

External links

• Pyrophosphoric acid at PubChem