On the electrical double layer between mercury and aqueous solutions of sodium citrate

Abstract

The adsorption of citrate ions at the Hg/aqueous CitNa3 interface was studied, using both differential capacity and electrocapillary measurements. The results contrast with those obtained previously by Barradas etal. The hump of the Cd–E curve increases as the concentration of the solution increases to 0.5 M, to diminish beyond 1 M. The plots of [Formula: see text] vs. q−1 are linear and parallel to one another for the different values of q, which is in agreement with the results obtained by other authors for different anions. A Frumkin isotherm is also associated for the adsorption process and, finally, the parameters are obtained for the interface, using a type of isotherm proposed by Grahame.