Diffusion in Non-ideal Liquid Mixtures

An equation proposed recently (Haase and Jansen, 1980) relates to the dependence on composition and temperature of the diffusion coefficient D and of the kinematic diffusion coefficient D* in a binary nonelectrolyte solution. This equation is now applied to our own measurements of the activity coefficients and of the diffusion coefficient in the non-ideal liquid system carbon tetrachloride + acetone at 20 °C and 40 °C over the entire range of compositions. (For 0 °C only values of D are available.) It turns out that the function D (.v), where .v denotes the mole fraction of one of the components, exhibits a minimum at each temperature, while D* (x) nearly represents a straight line. We establish a correlation between the deviations f rom Raoult 's Law and the sign of the difference D — D*.