Cu(OH)2↓ + 4NH3(soln.) -> [Cu(NH3)4]2+ + 2OH- — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Identify the reactants. Copper(II) hydroxide, Cu(OH)2↓, is an insoluble pale blue precipitate. Step 2: Analyze the complexation reaction. Adding ammonia solution provides strong ammine ligands that coordinate with the copper(II) ions to form a highly stable, soluble tetraamminecopper(II) complex, [Cu(NH3)4]^2+. Step 3: Because the addition of ammonia dissolves the solid copper hydroxide precipitate to form a clear deep blue solution, this is a precipitate dissolution reaction (type B). Thus, the correct option is (b).