Answer
See answers.
Work Step by Step
See the diagram, which is pressure (atm) versus volume (liters).
The gauge pressures must be expressed as absolute pressure for the ideal gas equation to be used. The initial gauge pressure of 3.5 atm is 4.5 atm absolute, and the other gauge pressure of 1.0 atm is 2.0 atm (absolute pressure).
The first segment, A, is the isothermal expansion to the lower pressure. The temperature is constant, so the ideal gas obeys “PV is constant”. The absolute pressure decreases by a factor of 2.25, so the volume increases by a factor of 2.25. Segment A is a piece of a hyperbola.
The second segment, B, is the cooling and compression at constant pressure back to the original volume. The path on the diagram is at constant pressure, thus horizontal.
The third segment, C, is the pressure increase at constant volume. This is a vertical path upward.
