Q. Identify the correct order of solubility in aqueous medium
A) CuS > ZnS > Na₂S
B) ZnS > Na₂S > CuS
C) Na₂S > CuS > ZnS
D) Na₂S > ZnS > CuS
Explanation
[Solution from source] Na₂S is an ionic alkali-metal sulphide and is freely soluble. ZnS (Ksp ≈ 10⁻²²) is sparingly soluble, and CuS (Ksp ≈ 10⁻³⁶) is far less soluble. So the order is Na₂S > ZnS > CuS. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.