Question

Identify the correct order of solubility in aqueous medium :

• A. $\ce{ Na2S > ZnS > CuS }$
• B. $\ce{ CuS > ZnS > Na2S }$
• C. $\ce{ZnS > Na2S > CuS }$
• D. $\ce{Na2S < CuS > ZnS}$

Answer 1

The Correct Option is A

To determine the solubility order of the given compounds in an aqueous medium, we need to consider the solubility products and general chemical properties of each compound.

1. Understanding Solubility: Solubility is the ability of a substance (solute) to dissolve in a solvent. In the case of ionic compounds, solubility is often determined by the solubility product constant (K_sp). A higher K_sp value indicates greater solubility in water.
2. Solubility Products of the Compounds: - Na₂S (Sodium sulfide): This compound is highly soluble in water. - ZnS (Zinc sulfide): This compound has a low solubility in water. - CuS (Copper sulfide): This compound is even less soluble compared to ZnS.
3. Order of Solubility: Based on the above understanding: - Na₂S is highly soluble. - ZnS is slightly soluble. - CuS is poorly soluble. Thus, the correct order of solubility is: Na₂S > ZnS > CuS.

Therefore, the correct answer is $\ce{ Na2S > ZnS > CuS }$.