Which one is correct group reagent for group cations? — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Cations Mn2+, Co2+, Zn2+, and Ni2+ belong to analytical Group IV. Step 2: Group IV cations require a basic medium with a high concentration of sulfide ions to exceed their relatively larger solubility products (Ksp) compared to Group II. Step 3: Therefore, the correct group reagent for these cations is H2S gas passed in the presence of NH4Cl and NH4OH, matching option (d).