Thallous oxide, Tl₂O

Thallous oxide, Tl₂O, is produced when thallium oxidises in air or oxygen at comparatively low temperatures. In warm air the oxidation of the metal proceeds rapidly, and at temperatures approaching dull redness thallic oxide commences to be formed in appreciable amount. Thallous oxide is best prepared by dehydrating thallous hydroxide at 100°. It is a heavy, black powder, which rapidly absorbs water, producing thallous hydroxide, and reacts with acids to produce thallous salts. It is attacked by chlorine and bromine with the production of chlorides and bromides of thallium and free oxygen. At about 300° it melts to a liquid which rapidly attacks glass. When heated to redness in hydrogen, thallous oxide is slowly reduced to metal; the reduction proceeds more readily in a stream of carbon monoxide.