Abstrakt: |
The kinetics of the oxidations of uranium tetraiodide and of triiodide by oxygen were studied over the temperature ranges from 55.0 to 66.5°C and from 88.5 to 103.5°C respectively. The experiments were carried out with an apparatus in which the column of a gas chromato-graph was replaced by an electric furance and traps of water vapor, oxygen and iodine. Most of the experiments were performed with the same partial pressure of oxygen (64 mmHg) and total flow rate (60 ml. per min.). The activation energies for the reaction of oxygen with uranium tetraiodide and triiodide were, respectively, 21.1 and 22.5 kcal. per mole. The rate of the formation of uranium trioxide was in agreement with the kinetics to be expected for reaction between a gas and a solid at a continuously diminishing spherical interface. |