Answer
w = -50.65 J
Work Step by Step
Since we are dealing with the expansion/compression of gases, the work is given by $w = -P\Delta V $. We have that the pressure is 1.0 atm and that the volume changes by 0.50L. Therefore:
w = -(1.0atm)*(0.50L) = -0.5 L-atm
Then to convert from L-atm to Joules we have:
-0.5 L-atm * (101.3J / 1 L-atm) = -50.65 J
