Potassium Aquo-chlor-ruthenate, K₂Ru(OH₂)Cl₅

Potassium Aquo-chlor-ruthenate, K₂Ru(OH₂)Cl₅, results on boiling a slightly acidified solution of potassium chlor-ruthenite; K₂RuCl₅, with alcohol; as also by heating the hydrated sesquioxide with hydrochloric acid and alcohol.

Upon evaporation the salt crystallises in orthorhombic octahedra, which are soluble in water. The solution yields with alkalies a dirty white precipitate which soon becomes black, thereby differing from solutions of the trichloride, which give an immediate black precipitate under such conditions.