Helium has (=1.67) is initially at a pressure of 18 atm, volume 1 L, and temperature 632 K. It expands isothermally until its volume is

Helium has (γ=1.67) is initially at a pressure of 18 atm, volume 1 L, and temperature 632 K. It expands isothermally until its volume is 3 L and then it is compressed at a constant pressure until its volume and temperature are such that an adiabatic compression will return the gas to its original state.

A. Sketch this cycle in a pV-diagram.

B. Find the volume and temperature after isobaric compression.

C. the work done during the cycle, and

D. the efficiency of the cycle.