Temperature and Concentration Dependence of Mutual Diffusion Coefficients of Some Binary Liquid Systems

Mutual diffusion coefficients are measured for ethanol-water, acetone-water, and acetone-chloroform systems by means of a three-compartment cell. In each case, the results cover the complete concentration range and temperatures from 25°C to around the normal boiling point. The diffusion coefficients ai the terminal concentrations and those at the normal boiling point are obtained by extrapolation of the experimental values. The uncertainty of the experimental diffusion coefficients is estimated to be f2.6%. These results are compared with the results computed from various prediction correlations. Most mass transfer and heat transfer calculations in chemical engineering employ mutual diffusion coefficients at the ambient and at the higher temperatures. These data are scarce because of experimental difficulties of measurement, particularly at the higher temperatures.