Strontium Phosphide, Sr₃P₂

Strontium Phosphide, Sr₃P₂, has been prepared by heating lampblack with strontium phosphate in the electric furnace. It forms reddish-brown crystals of density 2.68, fusible in the electric arc. It burns in fluorine at room temperature, in chlorine at 30° C., in bromine vapour at 175° C., in iodine vapour at red heat, in oxygen at 300° C., and in sulphur at a still higher temperature. It is decomposed by carbon at a high temperature but not by sodium at red heat, by dilute acids and gaseous acids but not by concentrated acids, sulphuretted hydrogen, ammonia, nor organic solvents. It changes rapidly in moist air, and is decomposed by water with the liberation of phosphoretted hydrogen. Oxidising agents attack it violently.