Mutual-diffusion of some transition metal halides

The diffusion of some zinc and cobalt salts in water have been measured using an improved version of the capillary technique. In this technique, diffusion proceeds in the absence of stirring in the bulk solution. The amount of diffusing substance which remains in the capillary is analyzed after a chosen time. Nanis' solution for three-dimensional diffusion from a capillary has been used to calculate the experimental values. The values of diffusion coefficient of zinc iodide, cobalt bromide and cobalt iodide have been obtained with a diffusion run time of four hours. A comparison has been made between the experimental and theoretical values obtained from Onsager-Fuoss theory. An attempt has also been made to explain the deviation between the experimental and theoretical values over the concentration range studied.