A mole of a monatomic ideal gas at point 1 (250 kPa, 15 L) is expanded isothermally until the volume is doubled at point 2. Then it is cooled isochorically until the pressure is 100 kPa at point 3. The temperature drops in this process. The gas is now compressed isothermally until its volume is back to 15 L, but its pressure is now 200 kPa (point 4). Finally, the gas is heated isochorically to return to point 1.

(a) Draw the four processes and label the points in the pV plane.

(b) Calculate the temperature at points 1 and 3.

(c) Find the total work done by the gas.