Calculate $H_{rxn}$ for the reaction:

CaO$(s)+C{O}_2(g)CaC{O}_3(s)$

Use the following reactions and given $H\text{'}$s:

$Ca(s)+C{O}_2(g)+\frac{1}{2}{O}_2(g)CaC{O}_3(s),H=-812\mathrm{.}8kJ$

$2Ca(s)+O_2(g)2$CaO$(s),H=-1269\mathrm{.}8kJ$