Question #20ae1

1 Answer
Apr 24, 2015

To answer any #Delta(X)_(rxn)# problem; where #X=H^0,S^0, or G^0# we can always use Hess's Law.

Hess's Law:
#Delta(G^0)_(rxn)=(Sum DeltaG (Products))-(Sum DeltaG(Reactants))#

For our reaction #2CO(g)+O_2(g)->2CO_2(g)#

Notice: You cannot omit the physical state for these problems, this is why I added the (g) and I'm going to assume (g) for all.

#Delta(G^0)_(rxn)=[(2mol CO_2g*-394.4 (kJ)/(mol))] -[(2mol COg*-137.3(kJ)/(mol))+(1mol O_2g*0(kJ)/(mol))]#

Notice: the mol units cancel out leaving our answer in kJ.

#Delta(G^0)_(rxn)=[-788.8kJ]-[-274.6kJ]#

#Delta(G^0)_(rxn)=-514.2kJ#