Reference electrodes reversibility

Ag(p%+ are fulfilled. When in the system (13) the reference electrodes reversible to anion X and cation are connected to the phase w and o respectively, the Gibbs adsorption... 

In this equation we added a new subscript, which has not been discussed so far. Instead of the potential E, used thus far, we have introduced E, to specify that the cell for which this equation is valid has a reference electrode that is reversible with respect to the anion in solution. What would have been the result if a reference electrode reversible with respect to the cation had been used We shall spare the reader the tedium of working through the equations again, presenting only the final result, which is similar to Eq. 28H, namely ... 

In the case of the study of the adsorption of molecular solutes at the polarizable interface, different tactics are often employed in data analysis. Suppose a study of the adsorption of pyridine is carried out at the mercury solution interface from an aqueous solution containing KCl. The Gibbs adsorption isotherm for this system using a reference electrode reversible to the CU anion is... 

The presence of ionic specific adsorption may be confirmed by examining the dependence of the PZC on electrolyte concentration. From the data presented in fig. 10.6, it is seen that the PZC measured with respect to a constant reference electrode is approximately independent of electrolyte concentration when ionic adsorption is absent. The classic example of such a system is NaF in water at an Hg electrode. However, when anion adsorption occurs the PZC shifts in the negative direction with increase in electrolyte concentration. This is most pronounced for the I anion in the case of the halides. When cations are adsorbed, the PZC shifts in the positive direction. The interpretation of the shift of the PZC with electrolyte concentration can be put on a sound thermodynamic basis when the electrode potential is measured with a reference electrode reversible to one of... 

The electrocapillary theory developed by Frumldn [15, 16] makes it possible to determine not only the electrode charge and pzc but also the relative surface excesses of various ions by treating the y, E-curves. Namely, in a binary 1,1-electrolyte solution, when we use a reference electrode reversible with respect to anion (see above in Electrode Potentials),... 

From these equations, three Lippmann equations can be derived depending on the choice of reference electrode reversible with respect to one of the ions present in the system. 

The potential of the working electrode is measured against a reference electrode reversible with respect to A ions ( a)... 

Reference electrode reversible with respect to K ions (Ak)... 

The transfer of ions across immiscible electrolyte interfaces (ITIES) can be described by a similar Butler-Volmer formalism and involves resolvation of the transferred ions. The flux of ions can be measured by the electronic current in the external circuit generated at symmetrical reference electrodes reversible to one of the ions. 

In this cell aj and a2 represent the reference electrodes reversible to either cation (Bj or B2) or anion (A or A2). The situation is described by the equations ... 

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