Combustion of 1 mole of benzene is expressed at

$\mathrm{C}_6 \mathrm{H}_6(\mathrm{l})+\frac{15}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow 6 \mathrm{CO}_2(\mathrm{~g})+3 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) \text {. }$

The standard enthalpy of combustion of $2 \mathrm{~mol}$ of benzene is $-^{\prime} x^{\prime} \mathrm{kJ}$. $x=$ __________.

Given :

1. standard Enthalpy of formation of $1 \mathrm{~mol}$ of $\mathrm{C}_6 \mathrm{H}_6(\mathrm{l})$, for the reaction $6 \mathrm{C}$ (graphite) $+3 \mathrm{H}_2(\mathrm{g}) \rightarrow \mathrm{C}_6 \mathrm{H}_6(\mathrm{l})$ is $48.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$.

2. Standard Enthalpy of formation of $1 \mathrm{~mol}$ of $\mathrm{CO}_2(\mathrm{g})$, for the reaction $\mathrm{C}$ (graphite) $+\mathrm{O}_2(\mathrm{g}) \rightarrow \mathrm{CO}_2(\mathrm{g})$ is $-393.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$.

3. Standard and Enthalpy of formation of $1 \mathrm{~mol}$ of $\mathrm{H}_2 \mathrm{O}(\mathrm{l})$, for the reaction $\mathrm{H}_2(\mathrm{g})+\frac{1}{2} \mathrm{O}_2(\mathrm{g}) \rightarrow \mathrm{H}_2 \mathrm{O}(\mathrm{l})$ is $-286 \mathrm{~kJ} \mathrm{~mol}^{-1}$.