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.
Black silver oxide is heated in a test tube to give metallic silver and oxygen gas. The gas is captured in a balloon. This demo can be used at the beginning of the general chemistry sequence to illustrate the process of the discovery of chemical elements.
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.
Silver reacts readily with sulfur or hydrogen sulfide (H2S) to produce silver sulfide (Ag2S), a dark-colored compound familiar as the tarnish on silver coins and other objects. Silver sulfide also forms silver whiskers when silver electrical contacts are used in an atmosphere rich in hydrogen sulfide.
