JEE Main Chemistry question
Ksp of CuS, Ag₂S and HgS are 10⁻³¹, 10⁻⁴⁴ and 10⁻⁵⁴ respectively. Select the correct order for their solubility in water:
Answer: (D)
Solution
s(CuS)=√(10⁻³¹)≈3.2×10⁻¹⁶; s(HgS)=√(10⁻⁵⁴)=10⁻²⁷; s(Ag₂S)=(10⁻⁴⁴/4)^(1/3)≈1.35×10⁻¹⁵. Order: Ag₂S>CuS>HgS.