Fe2+ and Fe3+ can be distinguished by : — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Discharging the dark brown color of an iodine (I2) solution requires reduction of iodine to colorless iodide (I-) ions. Step 2: Evaluate the options. Both sodium sulfide (Na2S) and aqueous sulfur dioxide (SO2) are powerful reducing agents that reduce I2 to I- while being oxidized to elemental sulfur and sulfate respectively. Step 3: Therefore, shaking iodine solution with either sodium sulfide (b) or sulfur dioxide (c) decolorizes the solution, making both options correct.