In this work an equation of state which was previously given for the hard convex body chain molecules was modeled to n-alkanes and refrigerants. The equation of state parameters and the application ranges of density and temperature were determined through fitting with the experimental data. It was found that the collision diameter and the nonspherical geometry parameter are temperature dependent and the relations were also given for their temperature dependencies. The compressibility factor, the reduced bulk modulus and the reduced isobaric expansion coefficient were calculated using the obtained parameters and compared with their experimental values. It was shown that the errors in the properties prediction are within experimental uncertainty. The results show that the equation of state is applicable for alkanes and refrigerants in both subcritical and supercritical region, but the error increases a little in the region away from the critical point.