New equipment for the determination of virial coefficients of pure substances and binary mixtures

A new equipment for the measurement of virial coefficients of pure substances and binary mixtures is described. It consists of an improved modification of the set‐up proposed by Eucken and Meyer in 1929. The development is based on a critical review of the existing methods particularly with respect to adsorption effects. In order to reduce the influence of adsorption on the accuracy of virial coefficients, an optimum range for gas density is recommended. The accuracy of the virial coefficients is better than 20 cm3 mol−1. The set‐up was employed for the measurement of virial coefficients of acetone and hexane in the range from 352.95 to 393.85 K. The results are in excellent agreement with data published in literature. Furthermore, cross‐virial coefficients of the binary system acetone/hexane were measured and interpreted.