Answer
a) The answer is below.
b) 13 J
c) 22 J
Work Step by Step
a) A PV diagram consists of pressure on the y-axis and volume on the x-axis. Thus, in order to draw this diagram, start at some point A and then use an exponential decay function to go to point B. Next, draw a point C that has the same x-coordinate as A and the same y-coordinate as B. Then, draw a straight line that connects B to the other two points.
b) We know that the work done between C and A is 0, for the volume does not change. Thus, we add the works done during the other two processes:
$W = W_{AB}+W_{BC}=35-22=13\ J$
c) As stated above, the work going from C to A is 0. Since $Q=-W$, the answer is the negative work done from B to C, which is $22\ J$.