In which of the following aqucous solutions is the degree of dissociation of water maximum?

Options

A. `NH_4Cl` solution
B. `CH_3COONa` solution
C. `CH_3COONH_4` solution
D. NaCl solution

Answer

To determine in which aqueous solution the degree of dissociation of water is maximum, we need to analyze the provided options and the reactions that occur when these salts are dissolved in water.

### Step-by-Step Solution:

1. **Understanding Degree of Dissociation of Water**:
The degree of dissociation of water refers to the extent to which water ionizes into hydrogen ions (H⁺) and hydroxide ions (OH⁻). The more H⁺ and OH⁻ ions produced, the higher the degree of dissociation.

2. **Analyzing the Given Solutions**:
We have three solutions to consider:
- Ammonium chloride (NH₄Cl)
- Sodium acetate (CH₃COONa)
- Ammonium acetate (CH₃COONH₄)

3. **Reactions in Each Solution**:
- **Ammonium Chloride (NH₄Cl)**:
When NH₄Cl is dissolved in water, it dissociates into NH₄⁺ and Cl⁻ ions. The NH₄⁺ can react with water to produce H⁺ and NH₃ (ammonia):
\[ NH₄^+ + H₂O \rightleftharpoons H^+ + NH₃ \]
This reaction produces H⁺ ions, but does not significantly contribute to the formation of OH⁻ ions.

- **Sodium Acetate (CH₃COONa)**:
When CH₃COONa is dissolved, it dissociates into Na⁺ and CH₃COO⁻ ions. The acetate ion (CH₃COO⁻) does not produce H⁺ ions but can react with water to produce OH⁻ ions:
\[ CH₃COO^- + H₂O \rightleftharpoons CH₃COOH + OH^- \]
This reaction produces OH⁻ ions but does not produce H⁺ ions.

- **Ammonium Acetate (CH₃COONH₄)**:
When CH₃COONH₄ is dissolved, it dissociates into NH₄⁺ and CH₃COO⁻ ions. The NH₄⁺ can produce H⁺ ions, and the CH₃COO⁻ can produce OH⁻ ions:
\[ NH₄^+ + H₂O \rightleftharpoons H^+ + NH₃ \]
\[ CH₃COO^- + H₂O \rightleftharpoons CH₃COOH + OH^- \]
This solution produces both H⁺ and OH⁻ ions, leading to a higher degree of dissociation of water.

4. **Conclusion**:
Among the three solutions, the ammonium acetate solution produces both H⁺ and OH⁻ ions, resulting in the maximum degree of dissociation of water. Therefore, the correct answer is **Ammonium Acetate (CH₃COONH₄)**.

### Final Answer:
The degree of dissociation of water is maximum in the aqueous solution of **Ammonium Acetate (CH₃COONH₄)**.