Which of the following is formed when As2S3 is warmed with NH4OH and H2O2? — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Hydrogen peroxide (H2O2) in an alkaline medium (NH4OH) acts as a powerful oxidizing agent. Step 2: When arsenic(III) sulfide (As2S3) is treated with this mixture, the arsenic(+3) is oxidized to its highest oxidation state (+5), forming arsenate ions (AsO43-), while sulfide is oxidized to sulfate. Step 3: Thus, the species formed containing arsenic is the arsenate ion, AsO43-, which corresponds to option (b).