HgI2↓ + 2KI -> K2[HgI4] — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Mercuric iodide (HgI2↓) is a scarlet-red insoluble precipitate. Step 2: Reacting it with excess potassium iodide (KI) forms a highly stable, soluble complex coordination compound, potassium tetraiodomercurate(II) (K2[HgI4]). Step 3: Since the precipitate dissolves completely to give a clear solution of the complex, this is a precipitate dissolution reaction (type B), corresponding to option (b).