Lead (Pb2+), zinc (Zn2+), silver (Ag+)can be precipitated by HCl and H2S. Hence, answer will be none of the above. (a) Lead cation react with hydrochloric acid to give white ppt. of lead chloride. Pb2++HCl⟶
PbCl2
(Whiteppt.)Leadchloride
↓ Lead cation reacts with hydrogen sulphide to form insoluble ppt. of lead sulphide. Pb2++H2S⟶
PbS
Leadsulphide
↓ (b) Zinc cation react with HCl to give white ppt. of zinc chloride. Zn2++HCl⟶
ZnCl2
Zincchloride
↓ Zinc cation reacts with H2S to give yellowish ppt. of zinc sulphide. Zn2++H2S⟶
ZnS
Zincsulphide
↓ (c) Silver cation reacts with hydrochloric acid to give white ppt. of AgCl (silver chloride). Ag++HCl⟶
AgCl
(Whiteppt.)Silverchloride
↓ Silver cation react with hydrogen sulphide to form black colour ppt. of Ag2mS (silver sulphide). Ag++H2S⟶