Assertion :When `H_(2)S` is passed through a solution of `CuSO_(4)` no precipitate of `CuS` is abtain until the solution is acidified with `HCI`
Reasion: The solution products constant of `CuS` is not so high as to require a high concen tration of `S^(2-)` for the precipitate of `CuS`

Options

A. If both (A) and (B) are correct and (R ) is the correct explqanation of (A)
B. If both (A) and (B) are correct but (R ) is not the correct explqanation of (A)
C. If (A) is correct ,but (R ) is incorrect
D. If (A) is incorrect ,but (R ) is correct

Explanation

To analyze the assertion and reason provided in the question, we can break it down step-by-step:

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that when hydrogen sulfide (H₂S) is passed through a solution of copper sulfate (CuSO₄), no precipitate of copper sulfide (CuS) is formed until the solution is acidified with hydrochloric acid (HCl).

- **Analysis**: This is true because H₂S can dissociate to produce sulfide ions (S²⁻), but the concentration of S²⁻ may not be sufficient to precipitate CuS in a neutral or basic solution.

2. **Understanding the Reason**: The reason given is that the solubility product constant (Ksp) of CuS is not high enough to require a high concentration of S²⁻ for the precipitation of CuS.

- **Analysis**: This statement is misleading. The Ksp of CuS is low, which means that it does require a certain concentration of S²⁻ ions for precipitation to occur. In fact, a higher concentration of S²⁻ ions is needed to exceed the Ksp value and form a precipitate.

3. **Conclusion on Assertion and Reason**:
- The assertion is true: CuS does not precipitate until the solution is acidified.
- The reason is false: The Ksp of CuS does require a higher concentration of S²⁻ for precipitation.

4. **Final Evaluation**: Since the assertion is true but the reason is false, we conclude that the correct answer is that the assertion is true and the reason is false.