There is mixture of Cu(II) chloride and Fe(II) sulphate. The best way to separate the metal ions fro β Qualitative and Quantitative Analysis Chemistry Question
Question
There is mixture of Cu(II) chloride and Fe(II) sulphate. The best way to separate the metal ions from this mixture in qualitative analysis is:
π‘ Solution & Explanation
Step 1: Cu2+ belongs to analytical Group II, while Fe2+ belongs to Group III/IV. Group II cations are selectively precipitated as sulfides in an acidic medium. Step 2: Passing H2S gas through a solution acidified with dil. HCl suppresses the sulfide ion concentration (common ion effect of H+), keeping it high enough to precipitate only the highly insoluble CuS (Ksp ~ 10^-36) while leaving Fe2+ in solution. Step 3: Thus, passing H2S in an acidic medium selectively precipitates copper(II) sulfide, separating it from Fe(II), corresponding to option (a).