Zinc Dichromate, ZnCr₂O₇

Zinc Dichromate, ZnCr₂O₇.3H₂O, is obtained by evaporation of a solution of zinc ^arbonate in cold aqueous chromic acid. It yields, when pure, orange-red crystals, but the colour is usually dark red. The crystals are hygroscopic and readily dissolve in water, by which the dichromate is decomposed on boiling.

The double salt, ZnCr₂O₇.2Hg(CN)₂.7H₂O, has been obtained.