The Application of Irreversible Thermodynamics to Transport Processes in Concentrated Binary Electrolyte Solutions

Transport processes in isothermal binary electrolyte solutions have been studied by means of an irreversible thermodynamic approach. Relationships between the experimentally accessible quantities of transport number, diffusion coefficient, and conductivity are presented in terms of the phenomenological coefficients Lij and Rij. The isotopic diffusion coefficients of chloride ion in rubidium and caesium chloride, caesium ion in caesium chloride, and of tritium-labelled water in lithium, sodium, potassium, rubidium, and caesium chloride solutions have been measured in the concentration range 0-2.5M. These have been combined with existing literature data in order to obtain the phenomenological coefficients representing isotope-isotope friction. The variations with concentration and relative magnitudes of these quantities have been discussed in terms of water structure and ionic environment. Equivalent conductances, transport numbers, and diffusion coefficients have been measured for solutions of cadmium iodide in the concentration range 0-1.0M. These data have been combined with activity and density data from literature sources and the phenomenological coefficients Lij and Rij obtained. The variation of these quantities with concentration has been discussed and interpreted in terms of the formation of complex species in the cadmium iodide system