Аннотация:The electrocapillary curves on mercury in K//4Fe(CN)//6 solutions have been obtained, and the potentials of 0. 5 M potassium amalgam have been measured. The dependence of the surface excess of ions on the electrode charge has been calculated. The need to use circuits without transfer for the calculation of the surface excess of ions in solutions of asymmetric electrolytes has been confirmed. It is shown that the occurrence of a reaction between K//3Fe(CN)//6 and Hg with the formation of sparingly soluble mercury salts distorts the true values of E//e//q and makes it possible to obtain sigma versus E curves in the K//3Fe(CN)//6/K//4Fe(CN)//6 redox system by electrocapillary and drop-weight methods.