Aqueous Diffusion Measurements by the Lamm Scale Method and Their Correlation with Membrane Diffusion Measurements

Abstract

The diffusion of potassium chloride, sodium chloride, potassium sulphate, and .sucrose in water is investigated by means of a simplified form of the Lamm scale method. The maximum height method of calculation is modified in such a way that the experimental procedure is less laborious than the original method. The diffusion coefficient values are obtained over a range of temperatures and the activation energies for free diffusion calculated. Comparisons are made with the predictions of the Debye-Hückel-Onsager theory and with the results of membrane diffusion measurements. The defects of the method are discussed and a more refined method is described by which it should be possible to calculate the concentration dependence of the diffusion coefficient and also the influence of solvent counterflow.