Differential electrolytic potentiometry with periodic polarisation. Part XXV. Direct and mark-space biased periodic current polarisation in acid-base titrimetry in acetic anhydride-acetic acid

Abstract

The applications of direct current and mark-space bias square wave differential electrolytic potentiometric techniques to acid-base titrations in an acetic anhydride-acetic acid mixed solvent have been examined. Antimony metal-metal oxide electrodes were used as indicating systems. Titration curve shapes are similar to those obtained from aqueous acid-base titrations, but the required current density and percentage bias are much higher. Several compounds that do not exhibit basic properties in water were titrated successfully with perchloric acid. The advantage of using an aprotic solvent in conjunction with acetic anhydride is demonstrated.