Names | |
---|---|
IUPAC name
Calcium diphosphate
| |
Other names
| |
Identifiers | |
3D model (JSmol)
|
|
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.029.292 |
E number | E450(vi) (thickeners, ...) |
MeSH | Calcium+pyrophosphate |
PubChem CID
|
|
UNII | |
CompTox Dashboard (EPA)
|
|
| |
| |
Properties | |
Ca2O7P2 | |
Molar mass | 254.053 g/mol |
Appearance | White powder |
Density | 3.09 g/cm3 |
Melting point | 1,353 °C (2,467 °F; 1,626 K) |
insoluble | |
Solubility | soluble in HCl, nitric acids |
Refractive index (nD)
|
1.585 |
Hazards | |
NFPA 704 (fire diamond) | |
Flash point | Non-flammable |
Related compounds | |
Other anions
|
Calcium phosphate |
Other cations
|
Magnesium pyrophosphate Sodium pyrophosphate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Calcium pyrophosphate (Ca2P2O7) is a chemical compound, an insoluble calcium salt containing the pyrophosphate anion. There are a number of forms reported: an anhydrous form, a dihydrate, Ca2P2O7·2H2O and a tetrahydrate, Ca2P2O7·4H2O. Deposition of dihydrate crystals in cartilage are responsible for the severe joint pain in cases of calcium pyrophosphate deposition disease (pseudo gout) whose symptoms are similar to those of gout.[1] Ca2P2O7 is commonly used as a mild abrasive agent in toothpastes,[citation needed] because of its insolubility and nonreactivity toward fluoride.[2]