摘要：

The reaction between uranium tetrafluoride and chlorine trifluoride has been studied between 17° and 193°C using the same basic technique as was used in an investigation of the uranium tetrafluoride-fluorine reaction. This consists essentially of following the change in weight of the solid phase using a spring balance. The mechanism and kinetics of reaction were shown to be substantially the same for chlorine trifluoride as fluorine. The reaction rate passes through a maximum at 105°C, falls to a minimum at 148°C and then rises again. An explanation of this unusual behaviour is suggested. In the regions 17–58°C and 156–194°C, within the limits of experimental accuracy, the Arrhenius equation relates the reaction-rate constant and the temperature of reaction; the activation energies determined for uranium tetrafluoride prepared by hydrofluorination were 5·6 and 3·4 kcal per mole respectively. A linear relationship is shown to exist near ambient temperature between the reaction rate and partial pressure of chlorine trifluoride. In the velocity range examined, gas velocity had no effect on the reaction rate.

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