Аннотация:The adsorption behavior of the system: 0.05 m M [(CH3)4N]BF4 + 0.05 (1 - m) M [(C4H9)4N]BF4 was studied at the Hg/H2O interface by measuring the capacitance C and interfacial tension-sigma as functions of electrode potential E. It could be inferred from the shape of the C vs. E and sigma vs. E curves (their adsorption-desorption maximum, the positive pzc shift which occurs as m is raised from 0 to 1) that TBA+ ions in the electric double layer are replaced by TMA+ ions when going to more negative values of electrode charge. The plots of E(q = 0) against log (1 - m) constituted evidence for the discreteness of TBA+ adsorption at the Hg/H2O interface in the system being examined. Calculations performed with the experimental data showed that basically the behavior of this system is determined by specific adsorption of the TBA+ ions and their electrostatic displacement by the relatively inactive TMA+ ions. However, calculations by the Hurwitz-Parsons method performed under the proviso that q and sigma are independent of m at the potential where the C vs. E curves merge, lead to the erroneous conclusion that specifically adsorbed TMA+ ions cause a charge reversal of the surface, and that their specific adsorption matches the Grahame-Parsons model.