Cadmium Chromate, CdCrO₄

Cadmium Chromate, CdCrO₄, may be obtained by heating a solution of the dichromate with cadmium hydroxide, in a sealed tube, at 200° C., when it separates as a bright orange-yellow crystalline powder. It is insoluble in water, which, when boiling, decomposes it. If the mother-liquor from the above preparation is allowed to stand for a time, it deposits crystals of the dihydrate CdCrO₄.2H₂O.

Basic cadmium chromates, e.g. 5CdO.2CrO₃.H₂O, have been described. Basic double salts, e.g. (NH₄)₂O.4CdO.4CrO₃.3H₂O and K₂O.4CdO.4CrO₃.3H₂O, are formed when an alkali chromate is added to solutions containing excess of cadmium salt; with excess of potassium chromate the double salt, K₂Cd(CrO₄)₂.2H₂O, results; sodium chromate yields only alkali-free basic salts. Several ammoniated compounds have been described.