Ionic solvation in water–Co-solvent mixtures. Part 18.—Free energies of transfer of single ions from water into water–2-methoxyethanol mixtures
Abstract
ΔG°t(H+), the free energy of transfer of the proton from water into water–co-solvent mixutres, has been determined experimentally for the co-solvent 2-methoxyethanol keeping the conditions water-rich. Specific criticisms of the method used are discussed and rejected . ΔG°t(X–) for simple anions has been calculated from ΔG°t(HX) leading to the calculation of ΔG°t(M+) from ΔG°t(MX). ΔG°t(i)e, the free energy of transfer of the charge alone, has been determined for organic cations and anions using ΔG°t(H+) found here, combined with values for the pK of acids and bases in water–2-methoxyethanol. ΔGintt, the difference in the partial molar free energy of interaction of a molecule with the solvent in transferring the molecule from water into the mixture has been determined for two electrically neutral organic bases. The values for ΔG°t(i), ΔG°t(i)e and ΔGintt(i) are compared among themselves and with values found in mixtures of water with other co-solvents.