Silver phosphate
Encyclopedia
Silver phosphate or silver orthophosphate is a light sensitive, yellow, water insoluble chemical compound composed of silver
and phosphate
ions of formula Ag3PO4.
with a soluble orthophosphate; its solubility product is 8.89×10-17 mol4dm-12. The precipitation reaction is analytically significant and can be used to in qualitatively or quantitative tests for phosphates.
This compound is dissolved by nitric acid, or by ammonia. 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. Depending on the method of preparation different crystal forms of silver phosphate can be produced of the same lattice structure.
, the precipitation of silver phosphate is also used in silver stain
ing of biological materials (after reduction to silver metal) - as a magnifying agent for phosphate.
Silver phosphate also found use in early photography as a light sensitive agent.
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.
Silver phosphate is also a potential material for incorporating silver ion antibacterial properties into materials.
ions. Like silver orthophosphate it is light sensitive. Silver orthophosphate turns red on exposure to light. It has a density of 5.306g/cm3 and a melting point of 585 °C. A hydrate also exists which decomposes at 110 °C.
Silver metaphosphate (AgPO3) (CAS No. 13465-96-8) 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..
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
and phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
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 nitrateSilver nitrate
Silver nitrate is an inorganic compound with chemical formula . This compound is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides...
with a soluble orthophosphate; its solubility product is 8.89×10-17 mol4dm-12. The precipitation reaction is analytically significant and can be used to in qualitatively or quantitative tests for phosphates.
This compound is dissolved by nitric acid, or by ammonia. 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. Depending on the method of preparation different crystal forms of silver phosphate can be produced of the same lattice structure.
Uses
As well as being important in analytical chemistryAnalytical chemistry
Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials. Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of...
, the precipitation of silver phosphate is also used in silver stain
Silver stain
Silver staining is the use of silver to selectively alter the appearance of the target.-Use in medicine:It is used to stain histologic sections. This kind of staining is important especially to show proteins and DNA. It is used to show both substances inside and outside cells...
ing of biological materials (after reduction to silver metal) - as a magnifying agent for phosphate.
Silver phosphate also found use in early photography as a light sensitive agent.
In 2010, silver phosphate was reported as having a high (90%) quantum yield
Quantum yield
The quantum yield of a radiation-induced process is the number of times that a defined event occurs per photon absorbed by the system. The "event" may represent a chemical reaction, for example the decomposition of a reactant molecule:...
as a photocatalyst for the visible light photochemical splitting of water, and for production of activated oxygen by the same method.
Silver phosphate is also a potential material for incorporating silver ion antibacterial properties into materials.
Other silver phosphates
Silver pyrophosphate Ag4P2O7 (CAS No. 13465-97-9) can be prepared as a white precipitate from reaction of silver(I) and pyrophosphatePyrophosphate
In chemistry, the anion, the salts, and the esters of pyrophosphoric acid are called pyrophosphates. Any salt or ester containing two phosphate groups is called a diphosphate. As a food additive, diphosphates are known as E450.- Chemistry :...
ions. Like silver orthophosphate it is light sensitive. Silver orthophosphate turns red on exposure to light. It has a density of 5.306g/cm3 and a melting point of 585 °C. A hydrate also exists which decomposes at 110 °C.
Silver metaphosphate (AgPO3) (CAS No. 13465-96-8) 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..