Chemistry - Thermochemistry Question with Solution | TestHub

The heat of combustion of solid benzoic acid at constant volume is $-321.30\mathrm{kJ}$ at $27^{\circ }\mathrm{C}$. The heat of combustion at constant pressure is $(-321.30-x\mathrm{R})\mathrm{kJ}$, the value of $x$ is _______.