CORRELATION OF THE HAMMETT EQUATION WITH THE SOLUBILITY AND DISSOCIATION-CONSTANTS OF BENZOIC-ACID IN AQUO-ETHANOLIC SOLUTIONS

The correlation of solubility and the dissociation constants of benzoic acids with Hammett equation in aquo-ethanolic solutions has been attempted. The poor correlation of the solubilities with the Hammett equation arises from the difference in the factors responsible for solubilisation processes. The dissociation constants in aquo-ethanolic mixtures can be well correlated with the Hammett equation and rho is found to vary linearly with the percentage of the organic solvents. The deviations from linearity at 16, 34 and 64 wt% of ethanol can be correlated with the structural peculiarities of the solvent mixtures.