MUTUAL DIFFUSION-COEFFICIENTS OF NA2SO4-H2O AND MGSO4-H2O AT 25-DEGREES-C FROM RAYLEIGH INTERFEROMETRY

The volume-fixed mutual diffusion coefficients of Na2SO4-H2O and MgSO4-H2O have been measured, from dilute solutions to near saturation, to an accuracy of 0.1-0.2% by free-diffusion Rayleigh interferometry. These results are compared to other available diffusion data for these salts. The diffusion coefficients of Na2SO4-H2O and MgSO4-H2O decrease regularly with increasing concentration, while those of many other salts exhibit both a maximum and a minimum as a function of concentration. A few diffusion coefficients have also been measured for KCl-H2O. © 1979 Plenum Publishing Corporation.