The metal capacitance of electrodes and the method for calculating the difference between potentials of zero charge of metals in the absence of specific adsorption of the solvent

Using Hg and the Ga metals in aqueous solutions as an example, the dependence of the potential difference between the metals on the magnitude of the charge sigma at sigma = const in the region sigma much less than 0, (Delta E(sigma)(Hg-M))(sigma much less than 0), is shown to be associated with different charge dependences of the surface potential of the metals, Delta chi(M)/Delta sigma, and, correspondingly, with the dependence of the metal capacitance of the electrodes, C-m(M), On the metal nature. The influence exerted by sigma on the difference of the metal potential drops at Hg and the Ga metals, Delta chi(Hg-M)/Delta sigma, is estimated. The difference (1/C-m(Hg)-1/C-m(M))(sigma) is shown to be independent of the magnitude of sigma and the solvent nature. The charge dependences of Delta E(sigma)(M1-M2) and (1/C-i(M1)-1/C-i(M2))(sigma) are analyzed as a function of the metal lyophilicity. The technique for calculating the difference between the potentials of zero charge undistorted by the specific adsorption of the solvent is proposed. The quantity sought for is shown to be independent of the solvent nature and to be close to the difference between the work functions for the metals in a vacuum.