The aqueous solution (s) of which of the following salts is (are) acidic in nature?

Options

A. `CuSO_4`
B. ` KCl`
C. ` CH_3COOK`
D. ` NH_4NO_3.`

Answer

To determine which of the given salts have an acidic aqueous solution, we need to analyze each salt based on the strength of the acids and bases they produce when dissolved in water.

### Step-by-Step Solution:

1. **Identify the salts**:
- Option 1: CuSO₄ (Copper(II) sulfate)
- Option 2: KCl (Potassium chloride)
- Option 3: CH₃COOK (Potassium acetate)
- Option 4: NH₄NO₃ (Ammonium nitrate)

2. **Analyze each salt**:
- **Option 1: CuSO₄**
- When dissolved in water, it dissociates into Cu²⁺ and SO₄²⁻ ions.
- Cu²⁺ can react with water to form Cu(OH)₂ (a weak base) and H₂SO₄ (a strong acid).
- Since H₂SO₄ is a strong acid and Cu(OH)₂ is a weak base, the solution will be acidic.
- **Conclusion**: CuSO₄ is acidic.

- **Option 2: KCl**
- When dissolved, it dissociates into K⁺ and Cl⁻ ions.
- K⁺ does not affect the pH, and Cl⁻ is the conjugate base of HCl (a strong acid).
- Since both ions come from a strong acid (HCl) and a strong base (KOH), the solution will be neutral.
- **Conclusion**: KCl is neutral.

- **Option 3: CH₃COOK**
- When dissolved, it dissociates into CH₃COO⁻ and K⁺ ions.
- K⁺ is neutral, while CH₃COO⁻ is the conjugate base of acetic acid (CH₃COOH), which is a weak acid.
- Therefore, the solution will be basic.
- **Conclusion**: CH₃COOK is basic.

- **Option 4: NH₄NO₃**
- When dissolved, it dissociates into NH₄⁺ and NO₃⁻ ions.
- NH₄⁺ can react with water to form NH₄OH (a weak base) and HNO₃ (a strong acid).
- Since HNO₃ is a strong acid and NH₄OH is a weak base, the solution will be acidic.
- **Conclusion**: NH₄NO₃ is acidic.

3. **Final Conclusion**:
- The salts that produce acidic solutions are CuSO₄ and NH₄NO₃.
- Therefore, the correct answer is **Option 1 (CuSO₄) and Option 4 (NH₄NO₃)**.