Calcium pyrophosphate

Calcium pyrophosphate
IUPAC name Calcium diphosphate
Other names Diphosphoric acid, calcium salt (1:2)
Identifiers
CAS number	7790-76-3 Y
PubChem	24632
ChemSpider	23034 Y
UNII	X69NU20D19 Y
MeSH	Calcium+pyrophosphate
ChEBI	CHEBI:32598 Y
Jmol-3D images	Image 1
SMILES [Ca+2].[Ca+2].[O-]P([O-])(=O)OP([O-])([O-])=O
InChI InChI=1S/2Ca.H4O7P2/c;;1-8(2,3)7-9(4,5)6/h;;(H2,1,2,3)(H2,4,5,6)/q2*+2;/p-4 Y Key: JUNWLZAGQLJVLR-UHFFFAOYSA-J Y InChI=1/2Ca.H4O7P2/c;;1-8(2,3)7-9(4,5)6/h;;(H2,1,2,3)(H2,4,5,6)/q2*+2;/p-4 Key: JUNWLZAGQLJVLR-XBHQNQODAN
Properties
Molecular formula	Ca2O7P2
Molar mass	254.053 g/mol
Exact mass	253.837108
Appearance	white powder
Density	3.09 g/cm3
Melting point	1353 °C, 1626 K, 2467 °F
Solubility in water	insoluble
Solubility	soluble in HCl, nitric acids
Refractive index (nD)	1.585
Hazards
EU Index	Not listed
NFPA 704	0 2 0
Flash point	Non-flammable
Related compounds
Other anions	Calcium phosphate
Other cations	Magnesium pyrophosphate Sodium pyrophosphate
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

Calcium pyrophosphate (Ca₂O₇P₂) is a chemical compound that can be formed by the reaction of pyrophosphoric acid and a calcium base or by strongly heating calcium phosphate or calcium ammonium phosphate.

It is commonly used as a mild abrasive agent in toothpastes.

Deposition of CPPD in articular joints causes an arthritis condition called pseudogout.

See also

• Calcium pyrophosphate deposition disease