The standard enthalpies of \( \mathrm{Al_2O_3} \) and \( \mathrm{CaO} \) are \( -1675 \, \mathrm{kJ\,mol^{-1}} \) and \( -635 \, \mathrm{kJ\,mol^{-1}} \) respectively.
For the reaction
\( 3\mathrm{CaO} + 2\mathrm{Al} \longrightarrow 3\mathrm{Ca} + \mathrm{Al_2O_3} \) the standard reaction enthalpy \( \Delta_r H^\circ = \) ______ kJ (Round off to the Nearest Integer).
