Uranous Arsenide, U₃As₄

Uranous Arsenide, U₃As₄, may be obtained by methods similar to those employed for the phosphide. When obtained by passing hydrogen over a fused mixture of sodium uranous chloride and sodium arsenide it is a greyish powder which readily burns in the air. It is sometimes obtained in a pyrophoric condition. An aluminium- containing product results when the aluminothermic process, using an oxide of uranium and arsenious oxide, is employed. The purest arsenide is obtained in the crystalline form when a mixture of hydrogen and arsenic vapour is passed over sodium uranium chloride. It is rapidly decomposed by nitric acid.