Question

Yellow ammonium sulphide solution is a suitable reagent used for the separation of :

• A. $HgS$ and $PbS$
• B. $PbS$ and $B{i}_2{S}_3$
• C. $B{i}_2{S}_3$ and $CuS$
• D. $CdS$ and $A{s}_2{S}_3$

Answer 1

The correct option is D $CdS$ and $A{s}_2{S}_3$

Yellow ammonium sulphide solution is a suitable reagent used for the separation of $CdS$ and $A{s}_2{S}_3$ as $A{s}_2{S}_3$ is soluble in yellow ammonium sulphide and the colour of the solution is yellow, this indicates the presence of $A{s}^{3+}$ ions.

$A{s}_2{S}_3+3(N{H}_4{)}_2{S}_2⟶2(NH4{)}_{3}As{S}_4+S$

So, the correct option is $D$