Predictive equations for self‐diffusion in liquids: A different approach

Simple relationships have been obtained which can be used to predict self‐diffusion coefficients of liquids with an average error of ±4%. In addition to the customary parameters, one of these equations contains the critical volume whereas the other uses Lennard‐Jones potential parameters Both relations were derived by using a general relation between transport coefficients of pure fluids and a molecular‐kinetic‐model of liquids. No use has been made either of the Stokes‐Einstein relation or the absolute rate theory. By applying the same relation between transport coefficients of pure fluids to gases, an equation has been obtained which can be used to calculate consistently molecular diameters in gases as a function of temperature, using Lennard‐Jones potential parameters.