Differential electrolytic potentiometry with periodic polarisation. Part XXIX. Precipitation and complexation titrations in anhydrous acetic acid

Abstract

The applications of direct current and mark-space biased square wave differential electrolytic potentiometry alongside zero-current potentiometry to single and mixed halide precipitation titrations with silver(I), to single halide precipitation or complexation titrations with mercury(I) and to single halide complexation titrations with mercury(II) in anhydrous acetic acid media have been examined, using silver, silver amalgam and gold amalgam electrodes. Mercury(I) offers no advantage over silver, which gives excellent results for single halides, particularly with silver electrodes, and chloride and bromide mixtures are fully resolved in this medium as well as chloride and iodide, particularly with silver amalgam electrodes, while bromide and iodide titrate to total halide only: chloride, bromide and iodide mixtures are resolved, but not accurately. The mercury(II) titrations are much improved in the anhydrous medium with respect to water; gold amalgam electrodes are favoured.