Barium Thiocyanate, Ba(CNS)₂

Barium Thiocyanate, Ba(CNS)₂, is prepared by boiling the cuprous or ammonium salt with barium hydroxide solution. It crystallises in long shining deliquescent needles with 2 molecules of water of crystallisation. It can also be formed by the action of thiocyanic acid on barium carbonate.

It loses its water of crystallisation at 120°-130° C., or at ordinary temperatures over sulphuric acid. It is very soluble in water, 100 c.c. of a solution saturated at 15° C. containing 103.7 grm. of the anhydrous salt.

Various double salts have been isolated - for example, BaHg(CNS)₄ and Ba[Hg(CNS)₃]₂, Ba(CNS)₂.2Hg(CNS)₂.4H₂O, Ba(CNS)₂.Hg(CN)₂, Ba(CNS)₂.2HgBr₂.5H₂O, and BaZn(CNS)₄.7H₂O, Ba₃Cr₂(CNS)₁₂.16H₂O, and Ba[(CrNH₃)₂(CNS)₃]₂(CNS)₂.

Barium thiocyanate forms compounds with ethyl alcohol, Ba(CNS)₂. 2C₂H₅OH and Ba(CNS)₂.C₂H₅OH, and also one with methyl alcohol, Ba(CNS)₂.2CH₃OH.