An analysis of the potential dependence of the apparent transfer coefficient and real activation enthalpy for a general two-step mechanism relating to an electrode reaction involving amalgam formation is presented. The significance of the analysis is discussed with respect to data for the reduction of Pb(II) at mercury in dimethylformamide solutions. Both the apparent transfer coefficient and real activation enthalpy for this reaction depend on the size of the tetraalkylammonium cation in solution and on the electrode potential. By analyzing the double-layer effects and potential dependence of the kinetic parameters, it is concluded that the reaction is complex and involves ion transfer rather than electron transfer in the rate-determining steps.