Answer
-173.0 J/K
Work Step by Step
We find:
$\Delta S^{\circ}_{rxn}=\Sigma n_{p}S^{\circ}(products)-\Sigma n_{r}S^{\circ}(reactants)$
$=[2\,mol\times S^{\circ}(CO_{2},g)]-[2\,mol\times S^{\circ}(CO,g)+ 1\,mol\times S^{\circ}(O_{2},g)]$
$=[2\,mol(213.6\,Jmol^{-1}K^{-1})]-[2\,mol(197.6\,Jmol^{-1}K^{-1})+1\,mol(205.0\,Jmol^{-1}K^{-1})]$
$=-173.0\,JK^{-1}$
