Electrode processes at mercury in the far cathodic potential region

Abstract

The reduction of K+ from 1 M KCl solution was studied in the presence of HCl at concentrations 0–5×10−3 M. The primary K+ reduction process is reversible at all values of pH within the limitations of the measuring technique. The primary process is accompanied by a parallel irreversible reaction due to an amalgam dissolution reaction. The characteristics of this process were similar at all values of pH to systems previously studied. An increase in the Warburg coefficients of the potassium ion reduction with decreasing pH was observed. The only plausible explanation was considered to be the blocking of the electrode by a product of the hydrogen ion reduction. The parallel amalgam decomposition reaction was similarly impeded. These results are compared briefly with previous studies of hydrogen ion reduction.