Chemistry: The Molecular Science (5th Edition)

The reaction will be favorable if Gibb's Free Energy is negative. Recall the equation for Gibb's Free Energy: $\Delta G^{\circ}=\Delta H^{\circ}-T\Delta S^{\circ}$. From this, we see that when looking for a favorable reaction, it is best for energy to be negative and for entropy to be positive. (Entropy is positive when there are more moles of gaseous products, and it will be negative when there are more moles of gaseous reactants.) Seeing this, we find that entropy and energy both do not favor this reaction.
The reaction will be favorable if Gibb's Free Energy is negative. Recall the equation for Gibb's Free Energy: $\Delta G^{\circ}=\Delta H^{\circ}-T\Delta S^{\circ}$. From this, we see that when looking for a favorable reaction, it is best for energy to be negative and for entropy to be positive. (Entropy is positive when there are more moles of gaseous products, and it will be negative when there are more moles of gaseous reactants.) Seeing this, we find that entropy and energy both do not favor this reaction.