pls answer a,b,c with work

(30 pts) There is one mole of an ideal gas in a closed cylinder with a piston. Its initial pressure is 1MPa and initial temperature is 300K. a) After undergoing an isothermal expansion, its final pressure is 0.5MPa. What's the volume of its final state? What's work for this process? b) After undergoing an adiabatic expansion, its final pressure is 0.5Mpa. Its constant pressure heat capacity (Cp) is 5R/2. What's the temperature of its final state? What's the volume of its final state? c) Please put above two processes on a P-V diagram and compare the work for the isothermal expansion and the adiabatic expansion and provide detailed explanations