The thermal effects of the protolytic equilibria of ethylenediamine-N,N,N',N'-tetrapropionic acid (EDTP) at 298.15 K and ionic strengths of 0.1, 0.5, and 1.0 (KNO3) were determined by direct calorimetry. The standard thermodynamic characteristics (pK°, ΔdisG°, ΔdisH°, ΔdisS°) of the stepwise dissociation reactions of this complexon were calculated using the combined results of thermochemical and potentiometric studies performed under identical experimental conditions. The results were compared with the corresponding data for related compounds.
S. N. Gridchin (Thu,) studied this question.