Zinc Cobalto-cyanide, Zn₂Co(CN)₆

Zinc Cobalto-cyanide, Zn₂Co(CN)₆, may be prepared as an orange-red precipitate by adding potassium cobalto-cyanide to an excess of zinc sulphate solution acidulated with sulphurous acid. It may be dried without change unless heated to 110-120° C. when it turns violet. It dissolves in excess of the potassium salt, yielding Zinc Potassium Cobalto-cyanide, K₂ZnCo(CN)₆.