Answer
$-3.1\times10^{3}\,J$
Work Step by Step
$pV=nRT$
$\implies V=\frac{nRT}{p}=\frac{1.0\,mol\times0.0821\,L\,atm\,K^{-1}mol^{-1}\times373\,K}{1.0\,atm}$
$=30.6\,L$
This volume is the change in volume.
$w=-P\Delta V=-(1.0\,atm)(30.6\,L)=-30.6\,L\cdot atm$
$=-30.6\,L\cdot atm\times\frac{101.3\,J}{1\,L\cdot atm}=-3.1\times10^{3}\,J$
