Ionic conductivity in the water-rich region of aqueous 2-butoxyethanol

Abstract

Ionic conductivities of HCl, KOH, and KCl were measured in aqueous solutions of 2-butoxyethanol (BE) at 25 °C. The quantity, Λ j ′ = σ/x j , which is almost proportional to the molar conductivity, was extrapolated to the infinite dilution x j → 0. σ is the conductivity and x j is the mole fraction of j(= HCl, KOH, or KCl). The plots of 0 Λ j ′, the value of Λ j ′ extrapolated to infinite dilution, against x BE showed a change in slope at x BE = 0.0175. The previous work from this laboratory indicated that the mixing scheme changes qualitatively at the same locus, x BE = 0.0175. By mixing scheme we simply mean the way in which BE and H 2 O molecules mix with each other. Assuming additivity in 0 Λ j ′ in terms of constituent ions, those values for H + OH − were calculated. Plots of [Formula: see text] thus calculated as a function of x BE in the water-rich region, 0 < x BE < 0.0175, suggest that the hydrogen bond probability decreases in the bulk of solution, as x BE increases. Keywords: aqueous 2-butoxyethanol, ionic conductivities, mixing schemes, hydrogen bond network.