The solubility of metal sulphides in saturated solution of `H_2S {H_2S= 0.1 M}` can be represented by `MS + 2H^+ Leftrightarrow M^(2+) +H_(2) S, K_(eq)=([M^(2+)][H_(2)S])/([H^(+]^2)`
The value of `K_(eq)` is given for few metal suphide. If conc. of each metal ion in solution is 0.01 M, which metal sulphides are selectively ppt at total `[H^+]= 1M` in saturated H2S solution.
Metal sulphides Mns ZnS Cos Pbs
`K_(eq)=([M^(2+)][H_(2)S])/([H^(+]^2)`

Options

A. Mns, ZnS, Cos
B. PbS, ZnS, Cos
C. PbS, ZnS
D. PbS

Answer

D