Write a balanced net ionic equation for each of the follow-ing dissolution reactions, and use the appropriate Ksp and Kf values in Appendix C to calculate the equilibrium constant for each. (b) Cu(OH)2 in aqueous NH3 to form [Cu(NH3)4]2+

Verified step by step guidance

1. Identify the dissolution reaction: Cu(OH)_2(s) dissolves in NH_3(aq) to form [Cu(NH_3)_4]^{2+}(aq).
2. Write the balanced chemical equation for the dissolution of Cu(OH)_2: Cu(OH)_2(s) ⇌ Cu^{2+}(aq) + 2OH^-(aq).
3. Write the complexation reaction: Cu^{2+}(aq) + 4NH_3(aq) ⇌ [Cu(NH_3)_4]^{2+}(aq).
4. Combine the dissolution and complexation reactions to form the net ionic equation: Cu(OH)_2(s) + 4NH_3(aq) ⇌ [Cu(NH_3)_4]^{2+}(aq) + 2OH^-(aq).
5. Calculate the equilibrium constant (K_eq) using the K_sp for Cu(OH)_2 and the K_f for [Cu(NH_3)_4]^{2+}: K_eq = K_sp * K_f.

Key Concepts

Net Ionic Equations

A net ionic equation represents the chemical species that are involved in a reaction, excluding spectator ions that do not participate in the reaction. It focuses on the ions and molecules that undergo a change during the reaction, providing a clearer picture of the actual chemical process. To write a net ionic equation, one must first write the complete ionic equation and then remove the spectator ions.

Solubility Product Constant (Ksp)

The solubility product constant (Ksp) is an equilibrium constant that applies to the solubility of sparingly soluble ionic compounds. It quantifies the extent to which a compound can dissolve in water, expressed as the product of the molar concentrations of the ions, each raised to the power of their coefficients in the balanced dissolution equation. Understanding Ksp is crucial for predicting whether a precipitate will form in a solution.

Formation Constant (Kf)

The formation constant (Kf) is a measure of the stability of a complex ion in solution, representing the equilibrium between the complex ion and its constituent ions. It is defined as the ratio of the concentration of the complex ion to the concentrations of the free ions, each raised to the power of their coefficients. A high Kf value indicates a stable complex, which is important for understanding the behavior of metal ions in coordination chemistry.