Effect of the hydroxyl ion produced by water reduction on the estimation of weak acid dissociation rates using the koutecky-levich analysis at a rotating disk electrode⋆

Kouteckẏ-Levich plots for the estimation of dissociation rates of weak acids from the “limiting” rotating disk electrode (RDE) current response yield intercepts thatdepend on the potential. The limiting kinetic current is progressively distorted by hydroxide ion produced by the parallel reduction of water. The effect of the weak acid composition, temperature, rotation speed and acid anion concentration on the magnitude of the limiting current distortion has been studied. Conditions for minimizing the effect of this distortion of the limiting RDE response are discussed, and a procedure is givenfor interpreting Kouteckẏ-Levich plots obtained using data contaminated by the parallelwater reduction process.