Cobalt Chromate, CoCrO₄

Cobalt Chromate, CoCrO₄, is prepared by heating cobalt carbonate and chromic acid solution for several hours at 185° C. in a sealed tube. It yields greyish black crystals, readily soluble in hot dilute nitric acid (contrast nickel chromate). The dihydrate, CoCrO₄.2H₂O, is obtained by the interaction of cobaltic acetate and potassium chromate. It yields bronze-coloured prisms or leaflets.