Silver phosphate

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
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[1]
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[2]
−120.0·10−6 cm3/mol
Structure
cubic
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamond
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).
Infobox references

Synthesis, reactions and properties

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 and 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

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

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

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
  1. 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..
  2. John Rumble (June 18, 2018). CRC Handbook of Chemistry and Physics (99 ed.). CRC Press. pp. 5–189. ISBN 978-1138561632.
  3. 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. 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. 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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