P4) A gas enters at condition of 10 bar and 500 C enters an expander, to be then exhausted at 2 bar. If the efficiency of the equipment is 0.8.

What is the temperature at the exit? What is the work output per mole? For the gas consider: A= 6, B=1 x 10-³ (K²), C=0, D=-1.5x10 (K²)