The viscosity of liquid mixtures

Abstract The theory of viscosity of liquid mixtures presented here is based on Eyring's theory of absolute reaction rates. The most important conclusions drawn are that for liquids the free energies of activation for viscosity are additive on a number fraction or mole fraction basis and that interactions of like and unlike molecules must be considered. Methanol‐toluene, benzene‐toluene, and cyclohexane‐heptane systems were analyzed with a three‐body model and found to fit within the accuracy of the experimental data. Acetone‐water mixtures fit a four‐body interaction much better. Indications are that to describe acetone‐water mixtures well would require consideration of seven‐ or eight‐body interactions.