Scandium chloride, ScCl₃

Scandium chloride, ScCl₃, may be prepared by heating scandia in a current of disulphur dichloride vapour and chlorine. It is a white solid which begins to sublime at 800°. It is hygroscopic and dissolves in water with evolution of heat, but it is insoluble in alcohol (Meyer and Winter).

When scandium hydroxide or oxide is dissolved in hydrochloric acid and the solution concentrated, fine white needles of the hexahydrate, ScCl₃.6H₂O, separate out. It is deliquescent and soluble in alcohol; dried at 100° it becomes converted into 2ScCl₃.3H₂O, and this loses hydrogen chloride when further heated (Crookes). An aqueous solution of scandium chloride reacts acid, owing to hydrolysis.

Scandium chloride forms a very soluble double chloride with ccesium chloride (Meyer and Wassjuchnow). The aurichloride, 3ScCl₃.2AuCl₃.21H₂O, forms readily soluble, yellow crystals, which lose water when carefully dried, and yield the hydrates with 8H₂O and 2H₂O, and finally the anhydrous salt (Crookes).