Self-Diffusion in Solutions

The self-diffusion of water was studied using D, T, and 18O isotopes as tracers. The results of these experiments showed that the identity of the tracer hardly influ­ences the self-diffusion coefficient, which is about 2 X 10_5 cm2/s. The activation energy of the self-diffusion of water is 18 kJ/mol. In electrolytes, the self-diffusion coefficient of water slightly depends on the electrolyte concentration. The carrier — free isotopes diffuse via the self-diffusion of water molecules (see Section 9.3).