Cobalt Molybdates

The anhydrous normal salt, Cobalt Molybdat, CoMoO₄, may be prepared by fusing together sodium molybdate, cobalt chloride, and sodium chloride, when it is obtained in greyish-green crystals. It is found with iron in the mineral pateraite. The monohydrate, CoMoO₄.H₂O, separates in bluish-violet crystals, when solutions containing cobalt chloride and sodium molybdate, or dimolybdate or ammonium paramolybdate, are allowed to crystallise. The crystals are only slightly soluble in hot water, but dissolve readily in acids or ammonium hydroxide. On heating, the anhydrous salt remains. The ammonio compound Co(NH₃)₂MoO₄.H₂O has been described.