Exploratory analysis in thermodynamics of equilibria. Classification and prediction of benzoic acid strength in aqueous-organic solvents

Abstract

Decisive rule for classification and prediction of benzoic acid strength from dielectric constant and Kamlet–Taft parameter of the mixed solvents (water–methanol, water–ethanol, and water–2-propanol) has been elaborated basing on the results of multivariate exploratory analysis. The rule has been verified using the independent experimental data on dissociation constant of benzoic acid in water–dioxane and water–dimethylsulfoxide mixtures. Two-parameter linear regression model of the Gibbs energy of benzoic acid dissociation as a function of the properties of aqueous-alcoholic solvents has been built, and the contributions of dielectric and cohesion medium properties to the decrease in the acid strength have been shown.