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

Options

A. `NH_(4)Cl` solution
B. `CH_(3)COONa` solution
C. `CH_(3)COONH_(4)` solution
D. Same in all

Answer

To determine in which of the following aqueous solutions the degree of dissociation of water is maximum, we need to analyze the effect of each solution on the ionization of water. The degree of dissociation of water refers to the extent to which water dissociates into hydrogen ions (H⁺) and hydroxide ions (OH⁻).

### Step-by-Step Solution:

1. **Understanding Water Dissociation**:
Water dissociates according to the equation:
\[ H_2O \rightleftharpoons H^+ + OH^- \]
The degree of dissociation is influenced by the concentrations of H⁺ and OH⁻ ions in the solution.

2. **Analyzing Each Option**:
- **Option 1: NH₄Cl Solution**:
- NH₄Cl is a salt of a weak base (NH₃) and a strong acid (HCl).
- In this solution, NH₄⁺ will hydrolyze to produce H⁺ ions, increasing the concentration of H⁺.
- Increased H⁺ concentration will shift the equilibrium to the left, reducing the degree of dissociation of water.
- **Conclusion**: This option will not maximize the degree of dissociation.

- **Option 2: CH₃COONa Solution**:
- CH₃COONa is a salt of a weak acid (acetic acid) and a strong base (NaOH).
- In this solution, CH₃COO⁻ will hydrolyze to produce OH⁻ ions, increasing the concentration of OH⁻.
- Increased OH⁻ concentration will also shift the equilibrium to the left, reducing the degree of dissociation of water.
- **Conclusion**: This option will not maximize the degree of dissociation.

- **Option 3: CH₃COONH₄ Solution**:
- CH₃COONH₄ is a salt formed from a weak acid (acetic acid) and a weak base (NH₃).
- In this solution, neither H⁺ nor OH⁻ concentrations will significantly increase because both ions will be produced in a balanced manner.
- Since there is no significant increase in either ion, the degree of dissociation of water will not be suppressed.
- **Conclusion**: This option will maximize the degree of dissociation of water.

3. **Final Answer**:
The solution in which the degree of dissociation of water is maximum is **Option 3: CH₃COONH₄ Solution**.