One mole of N₂ (C_v = R 2/5R) gas is originally at room temperature (20°C) and a pressure of 5 atm. It is allowed to expand adiabatically and quasi-statically until its pressure equals the room pressure of 1 atm. It is then heated at constant pressure until its temperature is again 20°C. During this heating, the gas expands. After it reaches room temperature, it is heated at constant volume until its pressure is 5 atm. It is then compressed at constant pressure until it is back to its original state.

(a) Construct an accurate PV diagram showing each process in the cycle.

(b) From your graph, determine the work done by the gas during the complete cycle.

(c) How much heat is added or subtracted from the gas during the complete cycle?

(d) Check your graphical determination of the work done by the gas in (b) by calculating the work done during each part of the cycle.