Barium Platinate, 3BaO.PtO₂

Barium Platinate, 3BaO.PtO₂, is formed when barium oxide is heated with the chloride or bromide in an open platinum crucible for several hours at 1100° C. It is more readily obtained by preparing first the amorphous platinate by heating platinic chloride with barium oxide and then fusing with barium chloride or bromide to obtain the crystalline product. It forms hexagonal prisms insoluble in acetic but soluble in hydrochloric acid. When very strongly heated it decomposes with the separation of platinum.