A simultaneous TG-DTA-MS study was made in a helium flow for an amorph
ous gel prepared by the addition of water to an ethanolic solution of
tungsten hexachloride before evaporating the solvent at ambient temper
ature. Four endothermic mass losses were observed at approx. 40-80, 13
0-170, 190-200 and 210-600 degrees C, The first was attributed to deso
rption of hydrochloric acid and water, The second was attributed to th
e simultaneous evolution of (1) hydrogen chloride and ethylene, and (2
) chloroethane. The third occurred very rapidly and was attributed to
the same gases as the second loss. The fourth occurred very slowly and
was attributed to the desorption of hydrogen chloride. The firing pro
cess of the gel was discussed on the basis of the decomposition mechan
isms.