Silver tungstate

Structural formula
General
Surname	Silver tungstate
other names	Silver tungsten oxide
Molecular formula	Ag 2 WO 4
Brief description	light yellow odorless solid
External identifiers / databases
CAS number 13465-93-5 EC number 236-708-3 ECHA InfoCard 100.033.357 PubChem 22045798 Wikidata Q24567348
properties
Molar mass	463.57 g mol −1
Physical state	firmly
Melting point	620 ° C
solubility	practically insoluble in water (150 mg l −1 at 20 ° C) soluble in potassium cyanide, ammonium hydroxide and nitric acid
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 .

Silver tungstate is an inorganic chemical compound of silver from the group of tungstates .

Extraction and presentation

Silver tungstate can be obtained by reacting a silver nitrate solution with sodium tungstate .

${\displaystyle \mathrm {2\ AgNO_{3}+Na_{2}WO_{4}\ \longrightarrow {}\ Ag_{2}WO_{4}\downarrow +2\ NaNO_{3}} }$

properties

Silver tungstate is a light yellow odorless solid that is practically insoluble in water. The connection comes in several modifications. The α-form has an orthorhombic crystal structure with the space group Pn 2 n (space group no. 34, position 3) (a = 10.820, b = 12.018, c = 5.900 Å). The metastable β-form has a hexagonal crystal structure with the space group P 6 ₃ (space group no. 173) or space group P 6 ₃ / m (space group no. 176) and the γ-form has a cubic crystal structure of the spinel type with space group Fd 3 m (space group number 227) (a = 9.352 Å).

use

Silver tungstate is used in the electronic and chemical industry (e.g. as a sensor material, additive to switch contacts or photocatalyst). It is also used in biochemistry for proteomics research.

Individual evidence

1. ↑ ^{a b c d e} data sheet Silver tungsten oxide, 99% from AlfaAesar, accessed on June 12, 2016 ( PDF )(JavaScript required) .
2. ↑ ^{a b c} data sheet Silver wolframat, 99.95% trace metals basis at Sigma-Aldrich , accessed on June 12, 2016 ( PDF ).
3. ^ ^{A b} William M. Haynes: CRC Handbook of Chemistry and Physics, 93rd Edition . CRC Press, 2016, ISBN 978-1-4398-8050-0 , pp. 102 ( limited preview in Google Book search).
4. ↑ A. Sreedevi, KP Priyanka, KK Babitha, N. Aloysius Sabu, TS Anu, T. Varghese: Chemical synthesis, structural characterization and optical properties of nanophase α-Ag2WO4. In: Indian Journal of Physics. 89, 2015, p. 889, doi : 10.1007 / s12648-015-0664-1 .
5. ^ AJ van den Berg, CAH Juffermans: The polymorphism of silver tungstate Ag2WO4. In: Journal of Applied Crystallography. 15, 1982, p. 114, doi : 10.1107 / S0021889882011510 .
6. ↑ Pablo S. Lemos, A. Altomare, AF Gouveia, IC Nogueira, L. Gracia, R. Llusar, J. Andrés, E. Longo, Laécio S. Cavalcante: Synthesis and characterization of metastable β-Ag2WO4: an experimental and theoretical approach. In: Dalton Trans .. 45, 2016, p. 1185, doi : 10.1039 / c5dt03754a .
7. ↑ Luís F. da Silva, Ariadne C. Catto, Waldir Avansi, Laécio S. Cavalcante, Juan Andrés, Khalifa Aguir, Valmor R. Mastelaro, Elson Longo: A novel ozone gas sensor based on one-dimensional (1D) α-Ag2WO4 nanostructures. In: Nanoscale. 6, 2014, p. 4058, doi : 10.1039 / C3NR05837A .
8. ↑ Werner Schatt , Klaus-Peter Wieters, Bernd Kieback (eds.): Powder metallurgy . Technologies and materials (=  VDI book ). 2., arr. and exp. Edition. Springer Science & Business Media, 2007, ISBN 978-3-540-23652-8 , pp. 419 ( limited preview in Google Book search).
9. ↑ Haihang Chen, Yiming Xu: Photoactivity and stability of Ag2WO4 for organic degradation in aqueous suspensions. In: Applied Surface Science. 319, 2014, p. 319, doi : 10.1016 / j.apsusc.2014.05.115 .