Lead Phosphides

Phosphorus is only slightly soluble in molten lead (about 1.5 per cent.). Most of that which is dissolved is thrown out as violet phosphorus (q.v.) when the lead solidifies, but some crystals of a phosphide are also formed. Precipitates are obtained by passing phosphine over lead acetate or into alkaline or ammoniacal alcoholic lead acetate solutions, consisting of unstable phosphides, such as Pb₃P₂, which is decomposed by acids with evolution of phosphine.