Question

A suspension containing insoluble substances $ZnS,CuS,HgS,{Ag}_{2}S,andFeS$, is treated with $2NHCL$. On filtering, the filtrate contained appreciable amounts of which one of the following groups?

• A. Zinc and mercury
• B. Silver and iron
• C. Copper and mercury
• D. Zinc, copper and iron

Answer 1

Answer: (D)

Zinc, copper and iron

$ZnS,CuS,andFeS$ are soluble in 2N HCl solution. Hence, the filtrate contains zinc copper and iron.
On the other hand, $HgS,and{Ag}_{2}S$ are insoluble in 2N HCl solution. Hence, Hg and Ag are not present in the filtrate.