At 25°C, the enthalpy of the following processes are given:
$\begin{aligned} & \mathrm{H}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \rightarrow 2 \mathrm{OH}(\mathrm{g}) \Delta \mathrm{H}^{\circ}=78 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \mathrm{H}_2(\mathrm{~g})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow \mathrm{H}_2 \mathrm{O}(\mathrm{g}) \Delta \mathrm{H}^{\circ}=-242 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \mathrm{H}_2(\mathrm{~g}) \rightarrow 2 \mathrm{H}(\mathrm{g}) \Delta \mathrm{H}^{\circ}=436 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \frac{1}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow \mathrm{O}(\mathrm{g}) \Delta \mathrm{H}^{\circ}=249 \mathrm{~kJ} \mathrm{~mol}^{-1}\end{aligned}$
What would be the value of X for the following reaction? _____ (Nearest integer)
$\mathrm{H}_2 \mathrm{O}(\mathrm{g}) \rightarrow \mathrm{H}(\mathrm{g})+\mathrm{OH}(\mathrm{g}) \Delta \mathrm{H}^0=\mathrm{X} \mathrm{kJ} \mathrm{mol}^{-1}$