Silver phosphate

Crystal structure
__ Ag +      __ P 5+      __ O 2−
General
Surname	Silver phosphate
other names	Silver orthophosphate Silver (I) phosphate
Ratio formula	Ag 3 PO 4
Brief description	yellow solid
External identifiers / databases
CAS number 7784-09-0 EC number 232-049-0 ECHA InfoCard 100.029.135 PubChem 159913 ChemSpider 140592 Wikidata Q2669979
properties
Molar mass	418.58 g mol −1
Physical state	firmly
density	6.390 g cm −3
Melting point	849 ° C
solubility	very poorly soluble in water soluble in nitric acid and ammonia
Refractive index	1.975
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 315-319-335 P: 261-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Silver phosphate (more precisely silver orthophosphate) is an inorganic chemical compound . Along with silver pyrophosphate Ag ₄ P ₂ O ₇ and silver metaphosphate AgPO _{3, it is} one of the phosphates of silver .

Extraction and presentation

Silver phosphate can be obtained by reacting potassium phosphate with silver nitrate .

${\displaystyle \mathrm {K_{3}PO_{4}+3\ AgNO_{3}\longrightarrow Ag_{3}PO_{4}+3\ KNO_{3}} }$

properties

Silver phosphate is a yellow solid that is very poorly soluble in water and gradually turns black when exposed to light.

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  Silver phosphate

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  Silver phosphate, precipitated, micrograph

Ag ₃ PO ₄ has a cubic crystal structure in the space group P 4 3 n (space group no. 218) with the lattice parameter a  = 603 pm and two formula units per unit cell . At 520 ° C, the transition to a likewise cubic high-temperature modification occurs, which crystallizes isotypically to γ-Na ₃ PO ₄ .

use

Silver phosphate is used in photographic emulsions and in drugs.

literature

• Yingpu Bi, Hongyan Hu, Shuxin Ouyang, Gongxuan Lu, Junyu Cao, Jinhua Ye: Photocatalytic and photoelectric properties of cubic Ag3PO4 sub-microcrystals with sharp corners and edges. (PDF; 10.7 MB) In: Chemical Communications. 48, 2012, p. 3748, doi : 10.1039 / c2cc30363a .

Individual evidence

1. ↑ ^{a b c d e f} data sheet Silver phosphate, 98% from Sigma-Aldrich , accessed on July 27, 2013 ( PDF ).
2. ^ ^{A b c} Jean d'Ans, Ellen Lax, Roger Blachnik: Pocket book for chemists and physicists . Springer DE, 1998, ISBN 3-642-58842-5 , pp. 290 ( limited preview in Google Book Search).
3. ^ ^{A b} Dale L. Perry: Handbook of Inorganic Compounds, Second Edition . Taylor & Francis US, 2011, ISBN 1-4398-1462-7 , pp. 483 ( limited preview in Google Book search).
4. ↑ External identifiers or database links to silver pyrophosphate : CAS number: 13465-97-9, EC number: 236-713-0, ECHA InfoCard: 100.033.361 , PubChem : 166821 , ChemSpider : 145953 , Wikidata : Q24630107 .
5. ↑ External identifiers of or database links to silver metaphosphate: CAS number: 13465-96-8, EC number: 236-712-5, ECHA InfoCard: 100.033.360 , PubChem : 16172267 , ChemSpider : 10790117 , Wikidata : Q4291662 .
6. ^ Theodore L. Brown, Bruce Edward Bursten, Harold Eugene LeMay: Chemistry: Studying compact . Pearson Deutschland GmbH, 2011, ISBN 3-86894-122-3 , p. 156 ( limited preview in Google Book search).
7. ^ R. Masse, I, Tordjman, A. Durif: Affinement de la structure cristalline du monophosphate d'argent Ag ₃ PO ₄ . Existence d'une forme haute témperature . In: Journal of Crystallography . No. 144 , 1976, pp. 76-81 , doi : 10.1524 / zkri.1976.144.1-6.76 .