Sodium Chromicyanide, Na₃[Cr(CN)₆]

Sodium Chromicyanide, Na₃[Cr(CN)₆].5H₂O or 8H₂O, crystallises only with difficulty. It may be prepared by the methods described below for the potassium salt, but the yellowish solution obtained yields a reddish-brown oil on evaporation, from which, with care, the pentahydrate may be obtained in small prisms. Needle-shaped crystals containing 8H₂O have also been obtained.