18. One mole of an ideal gas with CP=(5/2)R and CV=(3/2)R expands from P1=6 bar and T1=800K to P2=1 bar by each of the following paths: (a) Constant volume (b) Constant temperature (c) Adiabatically Assuming mechanical reversibility, calculate W,Q,U, and H for each process. Sketch each path on a single PV diagram