Benzene hexachloride, C 6 H 6 C1 61 is formed by the action of chlorine on benzene in sunlight.
By using hot acid the yellow anhydrous tungstic acid is precipitated, which is insoluble in water and in all acids except hydrofluoric. It may be obtained in a flocculent form by exposing the hexachloride to moist air.
The hexafluoride, WF 6, is a very active gaseous compound, which attacks glass and metals, obtained from tungsten hexachloride and hydrofluoric acid (Ruff and Eisner, Ber., 1905, 38, p. 74 2).
The dichloride, WC1 2, is an amorphous grey powder obtained by reducing the hexachloride at a high temperature in hydrogen, or, better, by heating the tetrachloride in a current of carbon dioxide.
The hexachloride, WC1 6, is obtained by heating the metal in a current of dry chlorine in the absence of oxygen or moisture, otherwise some oxychloride is formed; a sublimate of dark violet crystals appear at first, but as the hexachloride increases in quantity it collects as a very dark red liquid.