Which cation forms an insoluble chloride and an insoluble sulfide? (A) Ba2+ (B) Cu2+ (C) Mn2+ (D) Pb2+
From the general solubility pattern of ionic compounds, we know that all chlorides are soluble except for the chlorides of Lead (`Pb^2+` ), Mercury (`Hg^2+` and `Hg2^2+` ) and Silver (`Ag^+` ).
Again, considering solubility of sulphides, it can be observed that all sulphides are INSOLUBLE except for the sulphides of alkali metals (Na+, K+ etc.) and ammonium sulphide.
On this basis, from among of the cations (A) Ba2+ (B) Cu2+ (C) Mn2+ (D) Pb2+, it can be inferred that only lead (Pb2+) forms an insoluble chloride and an insoluble sulphide. So, the correct answer is option D.