Precise Measurements of Second Virial Coefficients of Simple Gases and Gas Mixtures in the Temperature Range Below 300 K

Abstract A new apparatus for measurements of second virial coefficients of gases or gas mixtures at room temperature is described. It was used to determine virial coefficients of He, H 2 , N 2 , CO 2 , NH 3 , and the interaction virial coefficient of Ar/NH 3 . Furthermore, low temperature interaction virial coefficients of Ar/NH 3 and H 2 /CO are reported and finally a critical revision of second virial coefficients of He, H 2 , Ar, N 2 , and CO at 77.3 K is presented. The virial coefficients are discussed in their relation to new intermolecular potentials.