Wikipedia

Silver phosphate

(Redirected from Silver pyrophosphate)

Silver phosphate or silver orthophosphate is a light sensitive, yellow, water-insoluble chemical compound composed of silver and phosphate ions of formula Ag3PO4.

Silver phosphate
Names
IUPAC name
Silver(I) phosphate
Other names
phosphoric acid, silver(I) salt; argentous phosphate; silver phosphate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.135 Edit this at Wikidata
EC Number
  • 232-049-0
UNII
  • InChI=1S/3Ag.H3O4P/c;;;1-5(2,3)4/h;;;(H3,1,2,3,4)/q3*+1;/p-3
    Key: FJOLTQXXWSRAIX-UHFFFAOYSA-K
  • [O-]P(=O)([O-])[O-].[Ag+].[Ag+].[Ag+]
Properties[2]
Ag3PO4
Molar mass 418.574 g/mol
Appearance Translucent yellow
becomes opaque or discolors when impure.
Odor odorless
Density 6.370 g/cm3
Melting point 849 °C (1,560 °F; 1,122 K)
0.00065 g/100 mL
8.89×10−17[1]
−120.0·10−6 cm3/mol
Structure
cubic
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
Safety data sheet (SDS) Sigma-Alrdich
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Synthesis, reactions and properties

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Silver phosphate is formed as a yellow solid precipitate by the reaction between a soluble silver salt, such as silver nitrate, with a soluble orthophosphate.[3] Its solubility product is 8.89×10−17 mol4·dm−2.[4][5] The precipitation reaction is analytically significant[6] and can be used in qualitative or quantitative analysis.[7]

This compound dissolves in aqueous ammonia.[3] Large crystals of silver phosphate form upon gradual evaporation of such ammoniacal solutions.

Its structure has been confirmed by X-ray crystallography.[8]

Uses

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The precipitation of silver phosphate is useful in traditional analytical chemistry. Precipitation of silver phosphate is also used in silver staining of biological materials (after reduction to silver metal) - as a magnifying agent for phosphate.[9]

Silver phosphate also found use in early photography as a light sensitive agent.[10]

Silver phosphate exhibits antibacterial properties.[11]

Research

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Silver phosphate is a high (90%) quantum yield photocatalyst for the visible light photochemical splitting of water and for production of activated oxygen by the same method.[12]

Other silver phosphates

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Silver pyrophosphate Ag4P2O7 (CAS No. 13465-97-9)[13] can be prepared as a white precipitate from reaction of silver(I) and pyrophosphate ions. Like silver orthophosphate it is light sensitive. Silver orthophosphate turns red on exposure to light.[14] It has a density of 5.306 g/cm3 and a melting point of 585 °C.[15] A hydrate also exists which decomposes at 110 °C.[15]

Silver metaphosphate (AgPO3) (CAS No. 13465-96-8)[16] is a white solid with a density of 6.370 g/cm3 and a melting point of 482 °C. A hydrate also exists which decomposes at 240 °C.[15]

References

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  1. ^ John Rumble (June 18, 2018). CRC Handbook of Chemistry and Physics (99 ed.). CRC Press. pp. 5–189. ISBN 978-1138561632.
  2. ^ Weast, Robert C., ed. (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, FL: CRC Press. p. B-145. ISBN 0-8493-0462-8..
  3. ^ a b Chisholm, Hugh, ed. (1911). "Phosphates" . Encyclopædia Britannica. Vol. 21 (11th ed.). Cambridge University Press. p. 475.
  4. ^ Ksp solubility constant for common salts www.solubilityofthing.com
  5. ^ SOLUBILITY PRODUCT CONSTANTS Archived 2012-06-15 at the Wayback Machine www.ktf-split.hr
  6. ^ Inorganic chemistry, Egon Wiberg, Nils Wiberg, Arnold Frederick Holleman, Academic Press, 2001 p.721 Google Books excerpt
  7. ^ F.H. Firsching (1961). "Precipitation of Silver Phosphate from Homogenous Solution". Anal. Chem. 33 (7): 873–874. doi:10.1021/ac60175a018.
  8. ^ R. Masse, I, Tordjman, A. Durif (1976). "Affinement de la Structure Cristalline du Monophosphate d'Argent Ag3PO4. Existence d'une Forme Haute Témperature". Zeitschrift für Kristallographie. 144 (1–6): 76–81. Bibcode:1976ZK....144...76M. doi:10.1524/zkri.1976.144.1-6.76.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  9. ^ Taichman, R. S.; Hauschka, P. V. (1992). "Effects of interleukin-1? And tumor necrosis factor-? On osteoblastic expression of osteocalcin and mineralized extracellular matrix in vitro" (PDF). Inflammation. 16 (6): 587–601. doi:10.1007/BF00919342. hdl:2027.42/44508. PMID 1459694. S2CID 21949509. Free version
  10. ^ Cassell's cyclopaedia of photography, Bernard Edward Jones, Ayer Publishing, 1973, p.401 'Phosphate plates and papers', googlebooks link
  11. ^ Nanocoated film as a bacteria killer 23/1/2009, www.nanowerk.com
  12. ^ Yi, Z.; Ye, J.; Kikugawa, N.; Kako, T.; Ouyang, S.; Stuart-Williams, H.; Yang, H.; Cao, J.; Luo, W.; Li, Z.; Liu, Y.; Withers, R. L. (2010). "An Orthophosphate Semiconductor with Photooxidation Properties under Visible-Light Irradiation". Nature Materials. 9 (7): 559–564. Bibcode:2010NatMa...9..559Y. doi:10.1038/nmat2780. PMID 20526323.
  13. ^ Silver pyrophosphate www.chemicalbook.com
  14. ^ Silver Compounds Archived 2013-12-03 at the Wayback Machine p.5, section 2.22, from Kirk-Othmer Encyclopedia of Chemical Technology, Authors: SAMUEL F. ETRIS (The Silver Institute), C. ROBERT CAPPEL (Eastman Kodak Company), via www.scribd.com
  15. ^ a b c Bulletin of the National Research Council, National Research Council (U.S.A), 1950, pp.56-57 google books link
  16. ^ Silver metaphosphate www.chemicalbook.com
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