Cupric Dichromate, CuCr2O7.2H2O, forms reddish-brown crystals on evaporation in the cold of a solution of cupric hydroxide in chromic acid. It becomes anhydrous at 100° C. It is deliquescent and soluble in water and alcohol. The aqueous solution on boiling yields the basic chromate. The following compounds have been prepared:
CuCr2O7.4NH3.2H2O; CuCr2O7.4(C6H5NH2); CuCr2O7.4(C5H5N); CuCr2O7.2(NH2.CH2.CH2.NH2).
Copper trichrornate and tetrachrornate are also known. |