Thermal diffusion of alkaline chlorides in D2O

Heats of transport of 0.01 m (molality) LiCl, NaCl, KCl, RbCl, and CsCl as well as the concentration dependence of the heat of transport of NaCl (up to 1.5 m) and KCl (up to 2 m) were studied potentiometrically from the measurement of thermoelectric powers of the silver--silver chloride thermocell at a mean temperature of 250C. Heats of transport of alkaline chlorides were found to be smaller in D2O than in H2O. Effective diffusion coefficients were also found to be smaller. The solvent isotope effect observed is discussed, and possible rationalization is given in terms of solvent properties, structural effects, and motions of ions and solvent molecules