Cadmium Chromate, CdCrO₄

Alkali chromates precipitate basic or double chromates from solutions of cadmium salts.

The normal anhydrous chromate, CdCrO₄, was obtained as a yellow powder, consisting of transparent prisms, by heating cadmium oxide, chromium trioxide, and water to 200° C. in a sealed tube.

The dihydrate, CdCrO₄.2H₂O, was obtained by heating the di-chromate with cadmium hydroxide in a sealed tube at 200° C. It is an orange crystalline powder, insoluble in water, soluble in acids, and goes brown on heating.

The ammoniates, CdCrO₄.NH₄.H₂O and CdCrO₄.4NH₄.3H₂O, have been prepared.

The following double chromates of cadmium and their ammoniates have been prepared: K₂O.CdO.4CrO₃.2H₂O; K₂CrO₄.CdCrO₄.2H₂O; (NH₄)₂CrO₄.CdCrO₄.2NH₄; 2(NH₄)₂CrO₄.2CdCrO₄.2NH₄.3H₂O.