Calcium pyrophosphate

Calcium pyrophosphate
Names
IUPAC name
Calcium diphosphate
Other names
  • Diphosphoric acid, calcium salt (1:2)
  • Dicalcium diphosphate
  • Dicalcium pyrophosphate
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.029.292 Edit this at Wikidata
E number E450(vi) (thickeners, ...)
MeSH Calcium+pyrophosphate
UNII
  • 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 checkY
    Key: JUNWLZAGQLJVLR-UHFFFAOYSA-J checkY
  • 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
  • [Ca+2].[Ca+2].[O-]P([O-])(=O)OP([O-])([O-])=O
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
1.585
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
0
0
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).
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Calcium pyrophosphate refers to any member of a series of inorganic compound with the formula Ca2P2O7(H2O)n. They are white solids that are insoluble in water. They contain the pyrophosphate anion, although sometimes they are referred to as phosphates. The inventory includes 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 because of its insolubility and nonreactivity toward fluoride.[2]

  1. ^ Calcium Pyrophosphate Deposition Disease at eMedicine
  2. ^ Klaus Schrödter; Gerhard Bettermann; Thomas Staffel; Friedrich Wahl; Thomas Klein; Thomas Hofmann (2012). "Phosphoric Acid and Phosphates". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_465.pub3. ISBN 978-3527306732.