Redox equilibria V. The locations of inflection points on titration curves for homogeneous reactions

Abstract

For titration curves of homogeneous redox reactions, it has been demonstrated that the inflection point corresponding to the maximum slope can coincide with the equivalence point. For any given pair of n -values, this can occur only at a particular value of Δ E o' . For commonly encountered pairs of n -values, the appropriate values of Δ E o' have been evaluated at 25 o . If, for a given pair of n -values, a value of Δ E o' is less than that presented, then the inflection point occurs before the equivalence point; if a value of Δ E o' is greater than that listed, then the inflection point occurs after the equivalence point. In general, the smaller the value of the asymmetry coefficient, the smaller is the value of Δ E o' required for the inflection point to coincide with the equivalence point.