DETERMINATION OF EQUILIBRIUM CONSTANTS OF PHOSPHORIC ACID FROM EXPERIMENTAL pH VALUE USING THE LEAST SQUARES METHOD III. DETERMINATION OF THE THIRD DISSOCIATION CONSTANT OF PHOSPHORIC ACID

Abstract

    The third dissociation constant of phosphoric acid was determined from experimental pHvalues which were obtained from potentiometric titrations of trisodium phosphate solutions.These results, according to an iterative approximation method using the least squaresalgorithm (with addition of ionic strength effect), are in good agreement with the values inreference literature.This method is described as a simple, effectual and accurate way for determining the acid- base's equilibrium constants.