The standard enthalpies of formation of $\mathrm{Al}_2 \mathrm{O}_3$ and CaO are $-1675 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and $-635 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively.
For the reaction
$3 \mathrm{CaO}+2 \mathrm{Al} \rightarrow 3 \mathrm{Ca}+\mathrm{Al}_2 \mathrm{O}_3$ the standard reaction enthalpy $\Delta_r \mathrm{H}^0=$ $\_\_\_\_$ kJ.
(Round off to the Nearest Integer).
