Three chlorides of indium are known: the trichloride, InC13j a deliquescent salt, formed by heating a mixture of the oxide and carbon in a current of chlorine; the dichloride, InCl2, obtained by heating the metal in hydrochloric acid gas; and the monochloride, InCl, which is prepared by distilling the vapour of the dichloride over metallic indium.
In a hydrated form it is obtained by the reduction of vanadyl monochloride, Voci, with sodium amalgam, being precipitated from the liquid by the addition of ammonia (Locke and Edwards, Zeit.
Thallic chloride, T1C1 3, is obtained by treating the monochloride with chlorine under water; evaporation in a vacuum gives colourless deliquescent crystals of T1C1,.H20.
Iodine combines with chlorine to form iodine monochloride, IC1, which may be obtained by passing dry chlorine over dry iodine until the iodine is completely liquefied, or according to R.
It crystallizes in long yellow needles and decomposes readily on heating into the monochloride and chlorine.