Medium Effects on Dissociation Constants of Maleic and Malonic Acids in Acetone–Water Binary Mixtures. A Thermodynamic Study

Abstract

The pK 1 and pK 2 values of maleic and malonic acids were determined by using a precise EMF method in acetone–water media of varying solvent compositions at different temperatures. The thermodynamic functions of dissociation (ΔH°, ΔG°, and ΔS°) have been computed, discussed and analyzed in terms of solute–solvent interactions. The pK values have been correlated with both the mole fraction of the organic solvent and the distance between the dicarboxyl groups in each acid.