Equation of state for gaseous propane determined from the speed of sound

An equation of state in the form of a truncated virial series has been developed for gaseous propane. Second, third, and fourth virial coefficients and their temperature derivatives were calculated from model two- and three-body iIntermolecular potentials, the parameters of which were fitted to experimental values of the speed of sound in the gas; 11o other data were used. The resulting model predicts accurately thermal and caloric properties of the gas over a wide range of temperatures at densities up to about one-quarter of the critical. The second and third [but not the fourth) virial coefficients are in very close agreement with directly measured values. To facilitate rapid calculation of thermodynamic properties, a look-up table for the virial coefficients and their temperature derivatives is provided together with a recommended means of iInterpolation.