General Approach of Le Hung

Le Hung presented a general theoretical approach for calculating the Galvani potential at the interface of two immiscible electrolyte solutions, e.g. aqueous (w) and organic solvent (s) [97]. Le Hung s approach allows the calculation of when the initial concentration, activity coefficients and standard energies of transfer of ions are known in both solutions. This can be considered as a quantitative realization of the idea implied in the above excerpt from the work by Verwey and Niessen [96]. 

According to Le Hung, one deals, in general, with a system composed of two liquid immiscible phases containing /f ions this can be described as follows  

In the equilibrium state, the electrochemical potentials of each jii ion are identical in both phases  

Using the definition of the electrochemical potential this can be rewritten in the form  

From Eq. (4) it follows that the Galvani potential can be calculated from the values of the standard potential and the activity of any ion participating in the equilibrium distribution. The standard Galvani potential is defined as follows  

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