Isothermal compressibility of saturated refrigerants: Chlorodifluoromethane and 1,1,1,2-tetrafluoroethane

A new five-parameter generalized van der Waals equation of state is employed for calculating the isothermal compressibility of saturated refrigerants such as chlorodifluoromethane and 1,1,1,2-tetrafluoroethane in the liquid and vapor states over a temperature range from the boiling point to the critical point. This generalized van der Waals equation of state differs from the known van der Waals equation by the modified repulsive and attractive terms. The parameters of the equation of state are determined through the characteristic thermodynamic parameters of the refrigerants. The generalized van der Waals equation-of-state parameters are compared with the known van der Waals equation-of-state parameters.