Answer
-1124 kJ
Work Step by Step
$\Delta H^{o}_{rxn}=\Sigma n_{p}\Delta H_{f}^{o}(products)-\Sigma n_{r}\Delta H_{f}^{o}(reactants)$
$=[2(\Delta H^{o}_{f,\,H_{2}O(l)})+2(\Delta H^{o}_{f,\,SO_{2}(g)})]-[2(\Delta H^{o}_{f,\,H_{2}S(g)})+3(\Delta H^{o}_{f,\,O_{2}(g)})]$
$=[2(-285.8\,kJ)+2(-296.8\,kJ)]-[2(-20.6\,kJ)+3(0)]$
$=-1124\,kJ$
