Kinetics of the reaction of hafnium tetrachloride vapour with solid sodium chloride

Abstract

The kinetics of the reaction of hafnium tetrachloride vapour with solid sodium chloride spheres to form sodium hexachlorohafnate have been studied as a function of pressure, temperature and sphere size. The course of the reaction was followed by weight gain measurements in an all-glass closed system using a quartz spring. Various kinetic models for gas-solid reactions were tested against the experimental data. Only the Carter-Valensi kinetic model gave a consistently good fit. Possible reaction mechanisms are discussed in the light of the pressure and temperature dependence of the specific rate constant in the Carter-Valensi model and in the inert marker experiments.