A sample of ${\mathrm{CH}}_4$ of 0.08g was subjected to combustion at ${27}^0\mathrm{C}$ in a bomb calorimeter. The temperature of the calorimeter system was found to be raised by $0.{25}^0 \mathrm{C}$ . If heat capacity of calorimeter is 18KJ, $∆\mathrm{H}$ for combustion of ${\mathrm{CH}}_4$ at ${27}^0\mathrm{C}$ is