A mixture contains 1 mole each of the following cations: . The mixture is dissolved in water, acidif — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

In an acidic medium with $H_2S$, only Group II cations precipitate. $Cu^{2+}$ precipitates as $CuS$. The remaining 4 cations ($Fe^{3+}, Zn^{2+}, Ba^{2+}, Mg^{2+}$) belong to higher groups (III, IV, V, VI) and stay in the filtrate. Note: $Fe^{3+}$ is reduced to $Fe^{2+}$ by $H_2S$ but remains in the solution as it does not precipitate.