Answer
The gas temperature is $360K$
Work Step by Step
We know, in case of isothermal process: $W=Q=nRTln(\frac{V_{f}}{V_{i}})$
Take any easy and clear point on graph. One of them is, $Q=1000J$ and it is already given that $V_{i}=0.20m^{3}$ and $V_{f}=V_{fs}=0.30m^{3}$ and $n=0.825mol$
So, $1000=0.825*8.314*T*ln(\frac{0.3}{0.2})$ which gives, $T=360K$
