2.For combustion of one mole of magnesium in an open container at 300 K and 1 bar pressure, $\Delta \mathrm{CH}^{\ominus}=-601.70 \mathrm{~kJ} \mathrm{~mol}^{-1}$ , the magnitude of change in internal energy for the reaction is _____ kJ. (Nearest integer)
(Given : $\mathrm{R}=8.3 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$ )