Gold dichloride, AuCl₂

At 170° C. dry chlorine unites with dried gold-powder to form the Gold dichloride, AuCl₂, a very hygroscopic, dark-red substance, decomposed by the action of moist air. The individuality of this compound has been a matter of dispute, and it has been assumed to be a molecular compound of the formula AuCl,AuCl₃, containing equimolecular proportions of aurous chloride and auric chloride. Thermochemical data indicate that this assumption is incorrect.