Final answer:
The expression for the equilibrium constant for the reaction AgCl(s) = Ag+(aq) + Cl¯(aq) is Ksp = [Ag+][Cl¯]. The solubility product, Ksp, for silver chloride is calculated to be 2.79 × 10¯10, which is less than 1. The expression for the equilibrium constant for the reaction Pb²+(aq) + 2Cl¯(aq) = PbCl₂(s) is Kc = [PbCl₂]. The value of Kc for this reaction is greater than 1, indicating that the forward reaction is favored.
Step-by-step explanation:
To write the expression for the equilibrium constant for the reaction represented by the equation AgCl(s) = Ag+(aq) + Cl¯(aq), we need to recall that reactants or products that are present as solids or liquids or the solvent do not affect the equilibrium expression. Therefore, the expression for the equilibrium constant for this reaction is simply:
Ksp = [Ag+][Cl¯]
The solubility product, Ksp, can be calculated from the concentrations of the silver and chloride ions. Using the given analytical data, we can calculate that Ksp = (1.67 × 10¯5)² = 2.79 × 10¯10. Since this value is very small, Ksp < 1.
For the reaction represented by the equation Pb²+(aq) + 2Cl¯(aq) = PbCl₂(s), the expression for the equilibrium constant is:
Kc = [PbCl₂]
Since the formation of solid PbCl₂ decreases the concentration of the reactants, the value of Kc for this reaction will be greater than 1, indicating that the forward reaction is favored.