Kinetic studies on the dehydration of trans-dichlorotetrammine-cobalt (III) iodate dihydrate

Abstract

The dehydration of trans-[Co(NH3)4Cl2)IO3·2H2O was studied isothermally by t.g.a. In the 0.1 < α < 0.8 range, where α is the fraction of the reaction complete, most of the runs gave the best fit to a second order rate law. Early stages of the reaction appear to follow a rate law based on reaction order while later stages (0.3 < α < 0.5) appear to be controlled by diffusion of H2O. The reaction in the 0.1 < α < 0.3 range gave a best fit to a third order rate law, while the 0.3 < α < 0.5 range gave the best fit to a three dimensional control rate law. The activation energy for the overall reaction was ca. 103 kJ mol−1. For α < 0.3 the activation energy was ca. 79.9 kJ mol−1, but for 0.3 < α < 0.5 it was ca. 110 kJ mol−1.