A gas (Molar mass \( = 280 \, \mathrm{g \, mol^{-1}} \)) was burnt in excess \( \mathrm{O_2} \) in a constant volume calorimeter and during combustion the temperature of calorimeter increased from \( 298.0 \, \mathrm{K} \) to \( 298.45 \, \mathrm{K} \). If the heat capacity of calorimeter is \( 2.5 \, \mathrm{kJ \, K^{-1}} \) and enthalpy of combustion of gas is \( 9 \, \mathrm{kJ \, mol^{-1}} \) then amount of gas burnt is ______ \( \mathrm{g} \). (Nearest integer)