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. |