Potassium Chromithiocyanate, K₃[Cr(SCN)₆]

Potassium Chromithiocyanate, K₃[Cr(SCN)₆].4H₂O, prepared by boiling a solution of a chromic salt with potassium thiocyanate, forms reddish-violet glistening crystals, of density 1.71 at 16° C. The salt is stable in the air and over sulphuric acid, but when heated to 110° C. it loses its water of crystallisation, and at higher temperatures decomposes. It dissolves in water, 1 part in 0.72 parts of water, yielding a red solution, which on boiling goes green, but on cooling returns to its original colour. By crystallising from aqueous alcohol a trihydrate may be obtained.