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.
The monoand dichlorides are decomposed by water with the formation of the trichloride, and separation of metallic indium.
When heated with phosphorus trichloride in a sealed tube to 360° C., potassium chlorochromate, phosphorus oxychloride, potassium chloride, and a complex chromium oxide (possibly Cr306) are produced (A.
It burns in an atmosphere of chlorine forming the trichloride; it also combines directly with bromine and sulphur on heating, while on fusion with alkalis it forms arsenites.
Arsenic trichloride, AsCl3, is prepared by distilling white arsenic with concentrated sulphuric acid and common salt, or by the direct union of arsenic with chlorine, or from the action of phosphorus pentachloride on white arsenic. It is a colourless oily heavy liquid of specific gravity 2.205 (o° C.), which, when pure and free from chlorine, solidifies at - 18°C., and boils at 132 °C. It is very poisonous and decomposes in moist air with evolution of white fumes.