Complete the following solubility product constant expression for the dissolution of silver chloride (AgCl) in water: AgCl(s) ⇌ Ag^+(aq) + Cl^-(aq). Which of the following correctly represents the K_{sp} expression for AgCl?

• A. K_{sp} = [AgCl]/([Ag^+][Cl^-])
• B. K_{sp} = [Ag^+][Cl^-]
• C. K_{sp} = [Ag^+]^2[Cl^-]
• D. K_{sp} = [Ag^+][Cl^-]/[AgCl]

Answer: (B)

Verified step by step guidance

1. Identify the dissolution reaction: AgCl(s) ⇌ Ag^{+}(aq) + Cl^{-}(aq). Here, solid AgCl dissociates into its ions in aqueous solution.
2. Recall that the solubility product constant, K_{sp}, is defined using the concentrations of the dissolved ions only, not the solid phase, because the activity of a pure solid is constant and incorporated into the equilibrium constant.
3. Write the general expression for K_{sp} as the product of the molar concentrations of the ions, each raised to the power of their stoichiometric coefficients: \(K_{sp} = [Ag^{+}]^{1} \times [Cl^{-}]^{1}\).
4. Since both ions have a coefficient of 1, the expression simplifies to \(K_{sp} = [Ag^{+}][Cl^{-}]\).
5. Therefore, the correct K_{sp} expression excludes the solid AgCl concentration and does not include any squared terms for the ions in this case.