Aqueous solution having highest pH is

Options

A. `0.1 M NH_4Cl`
B. `0.1 M NaCl`
C. `0.1 M (NH_4)_2 SO_4`
D. `0.1 M CH_3COONa`

Answer

To determine which aqueous solution has the highest pH among the given options, we need to analyze the nature of each salt based on the strengths of the acids and bases from which they are derived.

### Step-by-Step Solution:

1. **Identify the salts and their components**:
- Option 1: 0.1 M NH4Cl (Ammonium Chloride)
- Option 2: 0.1 M NaCl (Sodium Chloride)
- Option 3: 0.1 M (NH4)2SO4 (Ammonium Sulfate)
- Option 4: 0.1 M CH3COONa (Sodium Acetate)

2. **Analyze NH4Cl**:
- NH4Cl is formed from NH4OH (weak base) and HCl (strong acid).
- Since it is a salt of a weak base and a strong acid, it will be acidic in nature.
- Therefore, the pH of NH4Cl will be less than 7.

3. **Analyze NaCl**:
- NaCl is formed from NaOH (strong base) and HCl (strong acid).
- Both the acid and base are strong, leading to complete neutralization.
- Thus, NaCl is neutral, and its pH will be equal to 7.

4. **Analyze (NH4)2SO4**:
- (NH4)2SO4 is formed from NH4OH (weak base) and H2SO4 (strong acid).
- This salt is also derived from a weak base and a strong acid, making it acidic.
- Therefore, the pH of (NH4)2SO4 will also be less than 7.

5. **Analyze CH3COONa**:
- CH3COONa is formed from CH3COOH (weak acid) and NaOH (strong base).
- Since it is a salt of a strong base and a weak acid, it will be basic in nature.
- Thus, the pH of CH3COONa will be greater than 7.

6. **Compare the pH values**:
- NH4Cl: pH < 7 (acidic)
- NaCl: pH = 7 (neutral)
- (NH4)2SO4: pH < 7 (acidic)
- CH3COONa: pH > 7 (basic)

7. **Conclusion**:
- Among the given options, CH3COONa (sodium acetate) has the highest pH because it is basic in nature.

### Final Answer:
The aqueous solution having the highest pH is **0.1 M CH3COONa (Sodium Acetate)**.