Initially 0.900 mol of an ideal gas in a container occupies a volume of 3.40 l at a pressure of 3.80 atm with an internal energy U1 = 410.4 J. The gas is cooled at a constant volume until its pressure is 2.60 atm. Then it is allowed to expand at constant pressure until its volume is 8.00 l. The final internal energy is U2 = 660.7 J. All processes are quasi static. Draw this process on a PV diagram. What is the work done by the gas? Calculate work done by an ideal gas. Find the heat added during this process.