Since it is an isothermal process, $\Delta U=0$
$d q=-d W=P_{\text {ext }}\left(V_2-V_1\right)=3 L-\text { atm }=3 \times 101.3 J$
$\Delta S_{\text {surrounding }}-\frac{3 \times 101.3}{300} J K ^{-1}=-1.013 J K ^{-1}$
$\therefore \Delta S_{\text {surr }}=-1.013 J K ^{-1}$


| Column $I$ | Column $II$ |
| $(A)$ An insulated container has two chambers separated by a valve. Chamber $I$ contains an ideal gas and the Chamber $II$ has vacuum. The valve is opened. | $(p)$ The temperature of the gas decreases |
| $(B)$ An ideal monoatomic gas expands to twice its original volume such that its pressure $\mathrm{P} \propto \frac{1}{\mathrm{~V}^2}$, where $\mathrm{V}$ is the volume of the gas | $(q)$ The temperature of the gas increases or remains constant |
| $(C)$ An ideal monoatomic gas expands to twice its original volume such that its pressure $\mathrm{P} \propto \frac{1}{\mathrm{~V}^{4 / 3}}$, where $\mathrm{V}$ is its volume | $(r)$ The gas loses heat |
| $(D)$ An ideal monoatomic gas expands such that its pressure $\mathrm{P}$ and volume $\mathrm{V}$ follows the behaviour shown in the graph $Image$ | $(s)$ The gas gains heat |



