Thorium Oxychloride, ThOCl₂

Thorium Oxychloride, ThOCl₂, which is the first product of the interaction of thoria and carbon tetrachloride, may be isolated in the form of small colourless needles, which dissolve in water without decomposition. It is also formed when ThCl₄.7H₂O is heated to 250° C. Its heat of solution in water is 28,150 calories at 13° C. (Chauvenet). Crystallo-hydrates with 3, 5, and 6 molecules of water are known.