Abstract
The standard Gibbs free energies of transfer (ΔG
t° ) of halogen acids HX (X = Cl, Br or I) and alkali metal halides MX (M = Li, Na, K, Rb or Cs) as well as their constituent individual ions from water into tetrahydrofuran (THF) and its aqueous mixtures were determined from the e.m.f. measurements at 25 °C of the cells: glass electrode/HX, solvent/AgX, Ag; and glass electrode (M)/MX, solvent/AgX, Ag. The values of δg
t° of the individual ions on the molal, molar and mole fraction scales show the same trend of variation with solvent composition, i.e. they increase monotonically with increasing THF content in the solvent. The standard absolute potentials of different electrodes in these solvents as well as the radii of the solvated cations and the extent of their solvation in such media were computed. The results are briefly discussed in relation to ion-solvent interactions and ion solvation.