Dissociation equilibria in pyrophosphates and kinetics of degradation. Part 1.—Dissociation constants of pyrophosphoric acid

Abstract

Dissociation constants of pyrophosphoric acid have been obtained at 25, 50, 60, 65 and 70°C and at ionic strengths, 0.05, 0.10, 0.42, 1.00 and 1.14, from pH-titration curves of tetramethyl ammonium pyrophosphate against hydrochloric acid. Tetramethyl ammonium bromide was used to adjust the ionic strength. From the dissociation constants, enthalpies and entropies of dissociation have been calculated.