One mole of an ideal monoatomic gas initially at 300 K is expanded from an initial pressure of 10 atm to a final pressure of 1 atm. The molar heat capacity for constant volume for the gas is Cv = 3/2 R . Calculate ?U, ?H, q, w, and the final temperature (Tf) for each of the following paths: (a) An isothermal reversible expansion (b) An expansion against a constant external pressure of 1 atm in a thermally isolated (adiabatic) system. (c) An expansion against zero external pressure (against a vacuum) in an adiabatic system.