| Abstract
| - Steady-state voltammograms for reduction of acids ofvarious strengths in alcohols with excess supportingelectrolyte and without any supporting electrolyte can beused to infer charge type and strength of the acid on thebasis of the phenomenon of migration. For strong andmoderately weak acids (Ka/> 10-3) in alcohols, theratio of steady-state transport-limited current to diffusion-limited current, corrected appropriately for ion−ion interactions, the presence of ionic impurities, and changesin viscosity, for hydrogen ion reduction without supportingelectrolyte and with excess supporting electrolyte equals2. For acetic acid, which is very weak (Ka/< 10-6),the value of the steady-state transport-limited current is,under the experimental conditions applied here, independent of supporting electrolyte concentration. In thecase of a homogeneous acid−base equilibrium, a novelanalytical procedure yields diffusion coefficients of bothhydrogen ion and undissociated weak acid molecules fromthe diffusional and migrational currents. Limiting currentsobtained in alcohols with excess supporting electrolyteand without supporting electrolyte are compared bymeans of an extended formula that incorporates the ionicstrength dependence of diffusion coefficients.
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