Thermodynamics

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 \(-286 \mathrm{~kJ} \mathrm{~mol}^{-1}\).