Consider an aqueous solution that contains the following ions each with a concentration equal to 2.0×10^{- 12} M. [Zn²⁺] = 2.0×10^{- 12} M [Sn²⁺] = 2.0×10^{- 12} M [Cd²⁺] = 2.0×10^{- 12} M Which ion(s) will selectively precipitate if 5.0×10^{- 12} M Na₂S is added?
K _sp(ZnS) = 2.0×10^{- 22} K _sp(SnS) = 1.3×10^{- 23} K _sp(CdS) = 1.0×10^{- 24}

Question

Quizplus · Accepted Answer

The ion that will selectively precipitate is the one with the lowest solubility product (Ksp) when the concentration of sulfide ions (S^2-) is introduced. CdS has the lowest Ksp (1.0×10^-24), indicating it is the least soluble and will precipitate first under these conditions.

Consider an Aqueous Solution That Contains the Following Ions Each