Which one of the following salts give an acidic solution in water ?

Options

A. `CH_(3)COONa`
B. `NH_(4)Cl`
C. NaCl
D. `CH_(3)COONH_(4)`

Explanation

To determine which of the given salts produces an acidic solution in water, we can analyze each option based on the ions they release when dissolved.

### Step-by-Step Solution:

1. **Identify the Salts**: We have four options to consider:
- A: CH₃COONa (Sodium acetate)
- B: NH₄Cl (Ammonium chloride)
- C: NaCl (Sodium chloride)
- D: CH₃COONH₄ (Ammonium acetate)

2. **Analyze Option A (CH₃COONa)**:
- When CH₃COONa dissolves in water, it dissociates into CH₃COO⁻ (acetate ion) and Na⁺ (sodium ion).
- The acetate ion is the conjugate base of acetic acid (a weak acid), and it does not produce an acidic solution. Therefore, this option does not yield an acidic solution.

3. **Analyze Option B (NH₄Cl)**:
- NH₄Cl dissociates into NH₄⁺ (ammonium ion) and Cl⁻ (chloride ion).
- The ammonium ion is the conjugate acid of ammonia (a weak base) and can donate protons (H⁺) to the solution, making it acidic. Thus, this option produces an acidic solution.

4. **Analyze Option C (NaCl)**:
- NaCl dissociates into Na⁺ and Cl⁻ ions.
- Both ions are derived from strong acids and bases (NaOH and HCl), and they do not affect the pH of the solution. Therefore, NaCl does not produce an acidic solution.

5. **Analyze Option D (CH₃COONH₄)**:
- This salt dissociates into CH₃COO⁻ and NH₄⁺ ions.
- While NH₄⁺ can contribute to acidity, the presence of CH₃COO⁻ (which is a weak base) means that the solution will not be strongly acidic. The overall effect on pH is neutral or slightly acidic, but it is not definitively acidic.

6. **Conclusion**:
- Among the options analyzed, only **NH₄Cl (Option B)** produces an acidic solution when dissolved in water.

### Final Answer:
The salt that gives an acidic solution in water is **B: NH₄Cl**.

---