Chapter 16.7, Problem 16.7P

Consider the decomposition of gaseous N₂O₄:

     ${\text{N}}_{\text{2}}{\text{O}}_{\text{4}}\left(g\right) \to {\text{2 NO}}_{\text{2}}\left(g\right)\Delta H°=+\text{55}.\text{3 kJ};\Delta S°=+\text{175}.\text{7 J/K}$

(a)    Is this reaction spontaneous under standard-state conditions at 25 °C?

(b)    Estimate the temperature at which the reaction becomes spontaneous.