Which of the following reagents can be used to distinguish between a sulphite and a sulphate in solu — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Both sulfite (SO3^2-) and sulfate (SO4^2-) ions react with barium chloride (BaCl2) to form white precipitates of barium sulfite (BaSO3) and barium sulfate (BaSO4). Step 2: Upon adding dilute HCl, BaSO3 readily dissolves to yield soluble Ba2+ and pungent sulfur dioxide gas (SO2), whereas BaSO4 is highly stable and completely insoluble in dilute mineral acids. Step 3: This difference in acid solubility allows clear distinction of the two anions, matching option (c).