From an initial state where the pressure is $p_1,$ the temperature is $T_1,$ and the volume is $V_1,$ water vapor contained in a piston$-$

cylinder assembly undergoes each of the following processes:

Process $1-2$: Constant$-$temperature to $p_2=2p_1.$

Process $1-3$: Constant volume to $p_3=2p_1.$

Process $1-4$: Constant pressure to $V_4=2V_1.$

Process $1-5$: Constant temperature to $V_5=2V_1.$

On a $p-V$ diagram, sketch each process, identify the work by an area on the diagram, and indicate whether the work is done by$,$

or on$,$ the water vapor.