Sodium trimetaphosphate

Sodium trimetaphosphate[1]
Names
Other names
Sodium trimetaphosphate
Identifiers
3D model (JSmol)
ECHA InfoCard 100.029.171 Edit this at Wikidata
EC Number
  • 232-088-3
UNII
  • InChI=1S/3Na.H3O9P3/c;;;1-10(2)7-11(3,4)9-12(5,6)8-10/h;;;(H,1,2)(H,3,4)(H,5,6)/q3*+1;/p-3
  • O=P(OP(O1)([O-])=O)([O-])OP1([O-])=O.[Na+].[Na+].[Na+]
Properties
Na3P3O9
Molar mass 305.885 g/mol
Appearance colorless or white crystals
Density 2.49 g/cm3 (anhydrous)
1.786 g/cm3 (hexahydrate)
Melting point 53 °C (127 °F; 326 K) (hexahydrate, decomposes to anyhdrous)
22 g/100 mL
Solubility insoluble in alcohol
1.433 (hexahydrate)
Structure
triclinic (hexahydrate)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium trimetaphosphate (also STMP), with formula Na3P3O9, is one of the metaphosphates of sodium. It has the formula Na3P3O9 but the hexahydrate Na3P3O9·(H2O)6 is also well known. It is the sodium salt of trimetaphosphoric acid. It is a colourless solid that finds specialised applications in food and construction industries.[2]

Although drawn with a particular resonance structure, the trianion has high symmetry.[3]

Portion of the solid state structure of Na3P3O9·(H2O)6, as determined by X-ray crystallography. Highlighted is the P3O9 ring and some hydrogen bonding. Atoms are color coded as: purple = P, red = O, cyan = Na, white = H.[4]
  1. ^ Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, Florida: CRC Press. pp. 4–86. ISBN 0-8493-0594-2.
  2. ^ Klaus Schrödter; Gerhard Bettermann; Thomas Staffel; Friedrich Wahl; Thomas Klein; Thomas Hofmann (2008). "Phosphoric Acid and Phosphates". Ullmann's Encyclopedia of Industrial Chemistry. Ullmann’s Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_465.pub3. ISBN 978-3527306732. S2CID 94458523.
  3. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 530. ISBN 978-0-08-037941-8.
  4. ^ Tordjman, I.; Durif, A.; Guitel, J. C. (1976). "Structure Cristalline du Trimétaphosphate de Sodium Hexahydraté: Na3P3O9*6H2O". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 32 (6): 1871–1874. Bibcode:1976AcCrB..32.1871T. doi:10.1107/S0567740876006560.