Consider the reaction
$$ 2 \mathrm{H}_2 \mathrm{~S}(\mathrm{~g})+3 \mathrm{O}_2(\mathrm{~g}) \rightarrow 2 \mathrm{H}_2 \mathrm{O}(\mathrm{l})+2 \mathrm{SO}_2(\mathrm{~g}) $$
The magnitude of enthalpy change for the reaction in $\mathrm{kJmol}^{-1}$ is $\_\_\_\_$ . (Nearest integer) Given: $\Delta_{\mathrm{f}} \mathrm{H}^{!}\left(\mathrm{H}_2 \mathrm{~S}\right)=-20.1 \mathrm{~kJ} \mathrm{~mol}^{-1}$
$$ \begin{aligned} & \Delta_{\mathrm{f}} \mathrm{H}^{!}\left(\mathrm{H}_2 \mathrm{O}\right)=-286.0 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \Delta_{\mathrm{f}} \mathrm{H}^{!}\left(\mathrm{SO}_2\right)=-297.0 \mathrm{~kJ} \mathrm{~mol}^{-1} \end{aligned} $$