Solubilities and Free Energies of Transfer for p-Nitro-and p-Chloro-benzoic Acids in Aqueous Mixtures of 2-Methoxyethanol and 1,2-Dimethoxyethane

Department of Chemistry, North Bengal University, Darjeeling-734 430 Manuscript received 11 March 1988, revised 23 May 1988, accepted 6 July 1988 The solubilities of the p-nitro- and p-chloro-benzoic acids in 2-methoxye thanol (ME) + water and 1,2-dimethoxyethane (DME)+ water mixtures at 25° have been measured. The thermodynamic dissociation constants of the acids have been deter­mined from pH and solubility measurements. The free energies of transfer of p-nitro­-and p-chloro-benzoate ions [\(\bigtriangleup\)\(G^o_t\) ( \(A^-\))] from water to mixed solvent systems have been evaluated from the corresponding Δ \(G^o_t\) values of the acids and Δ\(G^o_t\)\(H^+\) values pre­viously determined in all the solvent systems. The overall dissociation behaviour of these acids is found to be dictated by the specific solute —solvent interactions besides the relative solvent basicities