Final answer:
The expression for the equilibrium constant for the reaction AgCl(s) = Ag+ (aq) + Cl¯ (aq) is Kc = [Ag+][Cl¯]. Since Ag+ and Cl¯ are more soluble as ions in solution compared to AgCl as a solid, the reaction favors the formation of products and Kc > 1.
The expression for the equilibrium constant for the reaction 3Ba²⁺(aq) + 2PO₄ ³⁻(aq) ⇌ Ba₃(PO₄)₂(S) is Kc = ([Ba³⁺][PO₄ ³⁻])² / ([Ba²⁺]³[PO₄³⁻]²). Since Ba₃(PO₄)₂ is insoluble and does not dissociate in solution, the reaction does not favor the formation of products and Kc < 1.
Step-by-step explanation:
(a) The expression for the equilibrium constant for the reaction represented by the equation AgCl(s) = Ag+ (aq) + Cl¯ (aq) is Kc = [Ag+][Cl¯]. Since the concentration of solid AgCl does not appear in the expression, and the concentrations of Ag+ and Cl¯ are not equal, Kc ≠ 1. Kc tells us the extent to which the reaction proceeds towards products.
If Kc > 1, it means that the concentration of products is greater than the concentration of reactants at equilibrium, indicating that the reaction favors the formation of products.
Since Ag+ and Cl¯ are more soluble as ions in solution compared to AgCl as a solid, the reaction proceeds towards products and Kc > 1.
(b) The expression for the equilibrium constant for the reaction represented by the equation 3Ba²⁺(aq) + 2PO₄ ³⁻(aq) ⇌ Ba₃(PO₄)₂(S) is Kc = ([Ba³⁺][PO₄ ³⁻])² / ([Ba²⁺]³[PO₄³⁻]²).
Since the concentrations of Ba³⁺, PO₄³⁻, and Ba²⁺ are not equal, and the concentration of solid Ba₃(PO₄)₂ does not appear in the expression, Kc ≠ 1. Kc tells us the extent to which the reaction proceeds towards products.
If Kc > 1, it means that the concentration of products is greater than the concentration of reactants at equilibrium, indicating that the reaction favors the formation of products.
In this case, since Ba₃(PO₄)₂ is insoluble and does not dissociate in solution, the reaction is not favored towards products and Kc < 1.