## The Transference Numbers of the Counter-Ions in Montmorillonite Paste as a Function of Water Film Thickness and Electrolyte Concentration

M. Tschapek and A. M. Grazán

Universidad Nactional de Sur, Avenida Alem 925, Bahia Blanca, R. Argentina

**Abstract:** The transference numbers of the counter ions in montmorillonite paste are determined as a function of the thickness of the water film (*h*) and of the diffuse double layer (1/κ).

From measured E.M.F. values of a cell with two liquid junction potentials (C′_{KCl} solution-paste-C″_{KCl} solution) and by applying the Henderson equation, the transference numbers *t*_{+} were calculated. It is shown that the transference numbers of the counter-ions, *t*_{+} → 1 if *h*_{K} → 0.