Gibbs free energies of transfer of the alkali-metal chlorides from water into t-butyl alcohol-water mixtures

Abstract

The standard Gibbs free energies of transfer Δ G XXX t of the alkali-metal chlorides MCI from water (W) into 5–90 wt.% t-butyl alcohol (TBA)-water mixtures (S) were determined from EMF measurements performed on the double cell Ag, AgCl¦MCl( m), S¦M(Hg)¦MCl( m), W¦AgCl,Ag at 25 °C in the molality range of MCI from 0.001–0.100 mol kg −1. The value of Δ G XXX t rises from Li + to Na + and falls from K + to Cs +, with a maximum between Na + and K + whose position depends on the solvent composition. The standard potentials of the cell M¦MCl( m), S¦AgCl,Ag in these 10 TBA-water mixtures were also determined. The results have been interpreted and discussed in terms of solute-solvent interactions.