Abstract: Standard Gibbs energies of transfer, GtΘ, of In(Ⅲ) from water to aqueous sucrose and aqueous glucose solutions(mass fraction of sucrose and glucose w=0, 0.10, 0.20, 0.30, 0.40 and 0.50) have been determined by polarography at (298±1) K. In aqueous sucrose and glucose solutions containing 5.0×10－2 mol•L－1 LiClO4, the reversible half-wave potential and the diffusion coefficients for In(Ⅲ) have been determined respectively. Values of GtΘ, obtained from the reversible half-wave potentials vs the ferrocene electrode scale, are negative and decrease with increasing concentration of sucrose and glucose, indicating increasing stability of In(Ⅲ) in sucrose-water and glucose-water solutions. The GtΘ values were split into electrostatic and chemical contributions. The decreased chemical contribution shows that the mixtures are more basic than pure water. The experimental results are discussed in terms of solute-solvent and solute-solute interactions in the ternary systems.

Key words: Polarography, Transfer of ion, Standard Gibbs energies of transfer, In(Ⅲ) ion