Methane enters a turbine (Figure 6-8) at T = 600 K and P = 10 bar and leaves at T = 400 K and P = 2 bar. How much work is produced for each mole of gas? Use the following data: van der Waals constants for methane are a  0.2303 pa-m⁶/mol² and b = 4.306 × 10^-5 m³/mol, and C_p* for methane is given in Appendix D.