Example 9.1: Non-Isothermal Mixing
A rigid insulated tank is divided into two parts, one that contains 50 mol of ethylene at 400 K, 1 bar, and the other contains 150 mol nitrogen at 300 K, 2 bar. The partition that divides the tank is removed and the contents are allowed to reach equilibrium. Determine the final pressure and temperature in the tank and determine the entropy generation. You may assume the pure gases and the final mixture to be in the ideal-gas state. The ideal-gas heat capacities of ethylene and nitrogen are 43 J/mol K and 29 J/mol K, respectively, and may be assumed independent of temperature.