Chapter 18, Problem 18.33CP

Consider again the dissociation reaction ${\text{A}}_{\text{2}}\left(\text{g}\right)$ $\stackrel{}{\rightleftarrows }$ 2 A(g)

(Problem 17.34).

(a) What are the signs (+, —, or 0) of the standard enthalpy change, $\Delta$ H°, and the standard entropy change, $\Delta$ S°, for the forward reaction?

(b) Distinguish between the meaning of $\Delta$ S° for the dissociation reaction and $\Delta$ S for the process in which the system goes from initial state 1 to the equilibrium state (pictured in Problem 17.34).

(c) What can you say about the sign of $\Delta$ G° for the dissociation reaction? How does $\Delta$ G° depend on temperature? Will $\Delta$ G° increase, decrease, or remain the same if the temperature increases?

(d) Will the equilibrium constant $K_P$ increase, decrease, or remain the same if the temperature increases? How will the picture for the equilibrium state (Problem 17.34) change if the temperature increases?

(e) What is the value of $\Delta$ G for the dissociation reaction when the system is at equilibrium?