Effect of Diffusion Coefficient Diversity on Steady-State Voltammetry When Homogeneous Equilibria and Migration Are Encountered

An exact treatment is developed to predict the steady-state limiting voltammetric current, I(L), for a system in which the reaction O(+) + A(-) ⇆ N occurs reversibly in solution, in the presence of supporting electrolyte C(+)A(-). Either or both O(+) and N undergo a one-electron reduction at the hemispherical microelectrode. The dependence of I(L) on the formation constant of the equilibration reaction, the electrolyte concentration, and the support ratio is derived for any trio of values of these parameters and for any combination of diffusivities of the O(+), N, and A(-) species.