Silver phosphate

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Silver phosphate
Fosforečnan stříbrný.PNG
Names
IUPAC name
Silver(I) phosphate
Other names
phosphoric acid, silver(I) salt; argentous phosphate; silver phosphate
Identifiers
7784-09-0
ChemSpider 140592
EC Number 232-049-0
Jmol 3D model Interactive image
PubChem 159913
  • 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]
Ag3O4P
Molar mass 418.57 g·mol−1
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
Structure
cubic
Vapor pressure {{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

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

Synthesis, reactions and properties

Silver phosphate is formed as a yellow precipitate by the reaction between a soluble silver compound, such as silver nitrate with a soluble orthophosphate;[2] its solubility product is 8.89×10−17 mol4dm−12.[3][4] The precipitation reaction is analytically significant[5] and can be used to in qualitatively or quantitative tests for phosphates.

This compound is dissolved by nitric acid, or by ammonia.[2] It can also be formed as large crystals by gradual loss of ammonia from an ammoniacal solution of silver phosphate; the reaction can be used in quantitative analysis of phosphate ions.[6] Depending on the method of preparation different crystal forms of silver phosphate can be produced of the same lattice structure.[6]

Uses

As well as being important in analytical chemistry, the precipitation of silver phosphate is also used in silver staining of biological materials (after reduction to silver metal) - as a magnifying agent for phosphate.[7]

Silver phosphate also found use in early photography as a light sensitive agent.[8]

In 2010, silver phosphate was reported as having a high (90%) quantum yield as a photocatalyst for the visible light photochemical splitting of water, and for production of activated oxygen by the same method.[9][10]

Silver phosphate is also a potential material for incorporating silver ion antibacterial properties into materials.[11]

Other silver phosphates

Silver pyrophosphate Ag4P2O7 (CAS No. 13465-97-9)[12] 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.[13] It has a density of 5.306g/cm3 and a melting point of 585 °C.[14] A hydrate also exists which decomposes at 110 °C.[14]

Silver metaphosphate (AgPO3) (CAS No. 13465-96-8)[15] is a white solid with a density of 6.370g/cm3 and a melting point of 482 °C. A hydrate also exists which decomposes at 240 °C.[14]

References

  1. Lua error in package.lua at line 80: module 'strict' not found..
  2. 2.0 2.1 Phosphates www.1911encyclopedia.org
  3. Ksp solubility constant for common salts www.solubilityofthing.com
  4. SOLUBILITY PRODUCT CONSTANTS www.ktf-split.hr
  5. Inorganic chemistry , Egon Wiberg, Nils Wiberg, Arnold Frederick Holleman , Academic Press , 2001] p.721 Google Books excerpt
  6. 6.0 6.1 Lua error in package.lua at line 80: module 'strict' not found.
  7. Lua error in package.lua at line 80: module 'strict' not found. Free version
  8. Cassell's cyclopaedia of photography , Bernard Edward Jones , Ayer Publishing , 1973 , p.401 'Phosphate plates and papers' , googlebooks link
  9. Lua error in package.lua at line 80: module 'strict' not found.
  10. Discovery of a Novel High Activity Photocatalyst Material: A Great Step Toward the Realization of Artificial Photosynthesis Discovery of a Revolutionary Oxidation Property in Silver Phosphate with Quantum Yield of Approximately 90% in Visible Light , 2010/06/07 , press release , National Institute for Materials Science (NIMS) Japan , www.nims.go.jp
  11. Nanocoated film as a bacteria killer 23/1/2009 , www.nanowerk.com
  12. Silver pyrophosphate www.chemicalbook.com
  13. Silver Compounds 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
  14. 14.0 14.1 14.2 Bulletin of the National Research Council , National Research Council (U.S.A) , 1950 , pp.56-57 google books link
  15. Silver metaphosphate www.chemicalbook.com