An external force acts on a piston such that the air expands to 200 kPa and 30 L. The ambient room temperature is 25°C. The piston-cylinder is initially at 180°C, 500 kPa, with a volume of 7 L. In its process of expansion, the work done by the system is 70% of the work done if it undergoes a reversible adiabatic process given the same initial conditions.

a) What is the final temperature of the air? (°C)
b) What is the amount of work done? (kJ)
c) Is the process possible? Why or why not?