Silver rust, Argentous oxide, Silver monoxide
3D model (JSmol)
CompTox Dashboard (EPA)
|Appearance||Black/ brown cubic crystals|
|Melting point||300 °C (572 °F; 573 K) decomposes from >=200 °C|
|0.013 g/L (20 °C)|
0.025 g/L (25 °C)
0.053 g/L (80 °C)
Solubility product (Ksp) of AgOH
|1.52·10-8 (20 °C)|
|Solubility||Soluble in acid, alkali|
Insoluble in ethanol
Heat capacity (C)
Std enthalpy of
Gibbs free energy (ΔfG?)
|GHS Signal word||Danger|
|H272, H315, H319, H335|
|P220, P261, P305+351+338|
|NFPA 704 (fire diamond)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|2.82 g/kg (rats, oral)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Silver oxide can be prepared by combining aqueous solutions of silver nitrate and an alkali hydroxide. This reaction does not afford appreciable amounts of silver hydroxide due to the favorable energetics for the following reaction:
With suitably controlled conditions, this reaction can be used to prepare Ag2O powder with properties suitable for several uses including as a fine grained conductive paste filler.
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 and possibly related hydrolysis products. It is soluble in ammonia solution, producing active compound of Tollens' reagent. A slurry of Ag2O is readily attacked by acids:
Like many silver compounds, silver oxide is photosensitive. It also decomposes at temperatures above 280 °C.
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.