Which of the following pairs of ions can be successfully separated by passing gas through their dilu — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Passing $H_2S$ in dilute $HCl$ precipitates only Group II cations. In (A), both $Bi^{3+}$ and $Sn^{4+}$ belong to Group II and will precipitate. In (B), $Hg^{2+}$ precipitates (Group II) but $Al^{3+}$ (Group III) does not. In (C) and (D), $Cu^{2+}$ precipitates (Group II) while $Zn^{2+}$ and $Ni^{2+}$ (Group IV) do not.