2.4g coal is burnt in a bomb calorimeter in excess of oxygen at 298K and 1 atm pressure. The temperature of the calorimeter rises from 298K to 300K. The enthalpy change during the combustion of coal  is - x kJ mol^-1. The value of x is (Nearest Integer) (Given : Heat capacity of bomb calorimeter 20.0 kJ K^-1. Assume coal to be pure carbon)

$\mathrm{C}+{\mathrm{O}}_{2\left(\mathrm{g}\right)}\Rightarrow {\mathrm{CO}}_2\mathrm{\Delta H}=?$
$\text{ Heat capacity of bomb calorimeter is }20 \mathrm{kJ} {\mathrm{K}}^{-1}\text{. }$
$=20\mathrm{kJ}\text{ of heat is required to raise the temperature by }1\mathrm{K}\text{. }$
$\text{ So. to raise temperature by }2\mathrm{K},40\mathrm{kJ}\text{ of heat is required. }$
$\therefore \mathrm{q}=40\mathrm{kJ}$
$\text{ Number of moles of }\mathrm{C}=\frac{2.4\mathrm{g}}{12\mathrm{g}/\mathrm{mol}}=0.2\mathrm{mol}$
$\text{ So, heat absorbed on combustion of }0.2\mathrm{mol}\text{ or }2.4\mathrm{g}\text{ of }C \mathrm{is} 40\mathrm{kJ}.$
$\text{ On combustion of }1\mathrm{mol}\text{ of carbon heat absorbed }$
$(∆\mathrm{H})=\frac{40\mathrm{kJ}}{0.2\mathrm{mol}}=200\mathrm{kJ}/\mathrm{mol}$