A gas flows through an adiabatic nozzle at a steady state, entering at P = 5 bar

Question:

A gas flows through an adiabatic nozzle at a steady state, entering at P = 5 bar and T = 400°C and leaving at P = 1 bar. Assuming the nozzle is reversible, what is the temperature of the exiting gas? Assume the gas has an ideal gas heat capacity of C_P* = 40 J/mol · K and follows the equation of state: where a = 1.00 cm/mol bar. K. RT P + aTP