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For the mixed oxide, see silver(I,III) oxide.
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| Names | |
|---|---|
| IUPAC name Silver(I) oxide | |
| Other names Silver rust, Argentous oxide, Silver monoxide | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider | |
| ECHA InfoCard | 100.039.946  |
| EC Number |
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| MeSH | silver+oxide |
PubChem CID | |
| RTECS number |
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| UNII | |
CompTox Dashboard (EPA) | |
InChI
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SMILES
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| Properties | |
Chemical formula | Ag2O |
| Molar mass | 231.735 g·mol−1 |
| Appearance | Black/ brown cubic crystals |
| Odor | Odorless[1] |
| Density | 7.14 g/cm3 |
| Melting point | 300 °C (572 °F; 573 K) decomposes from ≥200 °C[3][4] |
| 0.013 g/L (20 °C) 0.025 g/L (25 °C)[2] 0.053 g/L (80 °C)[3] | |
Solubility product (Ksp) of AgOH | 1.52·10−8 (20 °C) |
| Solubility | Soluble in acid, alkali Insoluble in ethanol[2] |
| −134.0·10−6 cm3/mol | |
| Structure | |
Crystal structure | Cubic |
| Pn3m, 224 | |
| Thermochemistry | |
Heat capacity (C) | 65.9 J/mol·K[2] |
Std molar | 122 J/mol·K[5] |
Std enthalpy of | −31 kJ/mol[5] |
Gibbs free energy (ΔfG˚) | −11.3 kJ/mol[4] |
| Hazards | |
| GHS pictograms |   [6] |
| GHS Signal word | Danger |
GHS hazard statements | H272, H315, H319, H335[6] |
GHS precautionary statements | P220, P261, P305+351+338[6] |
| NFPA 704 (fire diamond) | |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 2.82 g/kg (rats, oral)[1] |
| Related compounds | |
Related compounds | Silver(I,III) oxide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Silver(I) oxide is the chemical compound with the formula Ag2O. It is a fine black or dark brown powder that is used to prepare other silver compounds.
Preparation
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Silver(I) oxide produced by reacting lithium hydroxide with a very dilute silver nitrate solution
Silver oxide can be prepared by combining aqueous solutions of silver nitrate and an alkali hydroxide.[7][8] This reaction does not afford appreciable amounts of silver hydroxide due to the favorable energetics for the following reaction:[9]
- 2 AgOH → Ag2O + H2O (pK = 2.875[10])
With suitable control, this reaction could be used to prepare Ag2O powder with properties suitable for use as a fine grained conductive paste filler.[11]
Structure and properties
Ag2O features linear, two-coordinate Ag centers linked by tetrahedral oxides. It is isostructural with Cu2O. It "dissolves" in solvents that degrade it. It is slightly soluble in water due to the formation of the ion Ag(OH)−
2 and possibly related hydrolysis products.[12] It is soluble in ammonia solution, producing active compound of Tollens' reagent. A slurry of Ag2O is readily attacked by acids:
- Ag2O + 2 HX → 2 AgX + H2O
where HX = HF, HCl, HBr, HI, or CF3COOH. It will also react with solutions of alkali chlorides to precipitate silver chloride, leaving a solution of the corresponding alkali hydroxide.[12][13]
Like many silver compounds, silver oxide is photosensitive. It also decomposes at temperatures above 280 °C.[14]
Applications
This oxide is used in silver-oxide batteries. In organic chemistry, silver oxide is used as a mild oxidizing agent. For example, it oxidizes aldehydes to carboxylic acids. Such reactions often work best when the silver oxide is prepared in situ from silver nitrate and alkali hydroxide.
References
- ^ a b c "Silver Oxide MSDS". SaltLakeMetals.com. Salt Lake Metals. Retrieved 2014-06-08.
- ^ a b c Lide, David R. (1998). Handbook of Chemistry and Physics (81 ed.). Boca Raton, FL: CRC Press. pp. 4–83. ISBN 0-8493-0594-2.
- ^ a b Perry, Dale L. (1995). Handbook of Inorganic Compounds (illustrated ed.). CRC Press. p. 354. ISBN 0849386713.
- ^ a b http://chemister.ru/Database/properties-en.php?dbid=1&id=4098
- ^ a b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN 978-0-618-94690-7.
- ^ a b c Sigma-Aldrich Co., Silver(I) oxide. Retrieved on 2014-06-07.
- ^ O. Glemser and H. Sauer "Silver Oxide" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1037.
- ^ Janssen, D. E.; Wilson, C. V. (1963). "4-Iodoveratrole". Organic Syntheses.; Collective Volume, 4, p. 547
- ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
- ^ Biedermann, George; Sillén, Lars Gunnar (1960). "Studies on the Hydrolysis of Metal Ions. Part 30. A Critical Survey of the Solubility Equilibria of Ag2O". Acta Chemica Scandinavica. 13: 717. doi:10.3891/acta.chem.scand.14-0717.
- ^ US 20050050990A1, Harigae, Kenichi & Yoshiyuki Shoji, "Fine-grain silver oxide powder", published 2005-03-10
- ^ a b Cotton, F. Albert; Wilkinson, Geoffrey (1966). Advanced Inorganic Chemistry (2nd Ed.). New York:Interscience. p. 1042.
- ^ General Chemistry by Linus Pauling, 1970 Dover ed. p703-704
- ^ Merck Index of Chemicals and Drugs Archived 2009-02-01 at the Wayback Machine, 14th ed. monograph 8521
External links
- Annealing of Silver Oxide – Demonstration experiment: Instruction and video
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