Acid-base indicator transition ranges in pyridine.

ABSTRACT

The transition ranges of thirteen acid-base indicators in pyridine have been measured by visual and by photometric means. The transition ranges are given in terms of potentials measured with a glass - modified calomel electrode system. These data permit the selection of a suitable indicator for the titration in pyridine of any acid or acid mixture which does not give highly coloured products and has a good potentiometric break at the equivalence point.