Chapter 3, Problem 3P

The decomposition of crystalline N₂O₅ ${\text{N}}_{\text{2}}{\text{O}}_{\text{5}}\text{(s)}\to {\text{2NO}}_{\text{2}}\text{(g)}\text{+}\frac{\text{1}}{\text{2}}{\text{O}}_{\text{2}}\text{(g)}$ is an example of a reaction that is thermodynamically favored, even though it absorbs heat. At 25^o C we have the following values for the standard state enthalpy and free energy changes of the reaction:

$\Delta$ H = + 109kJ/m01
$\Delta$ G^o = -30.5kJ/m01

a. Calculate $\Delta$ S^o at 25^o C.

b. Why is the entropy change so favorable for this reaction?