4. 5 moles ideal gas is initially at 30 C and 101.325 Pa. The gas undergoes a reversible change at constant enthalpy (H = 0) to a final state with four times initial volume. Please calculate q, w, and U for the process.

5. 10 moles of an ideal gas expand isothermally and reversibly from a pressure of 10 atm to 2 atm at 300 K. Calculate the work it has done to the surroundings.