Which of the following aqueous solutions remain alkaline after electrolysis ?

Options

A. `CH_(3)COONa`
B. `KNO_(3)`
C. `NaCl`
D. `LiF`

Explanation

To determine which aqueous solutions remain alkaline after electrolysis, we will analyze each option step by step.

### Step 1: Analyze CH3COONa (Sodium Acetate)
- **Electrolysis Reaction**:
- At the cathode, water is reduced to form hydroxide ions (OH⁻) and hydrogen gas (H₂).
- At the anode, the acetate ion (CH₃COO⁻) is oxidized, producing ethene (C₂H₄) and carbon dioxide (CO₂).
- **Result**: The production of hydroxide ions makes the solution basic.

### Step 2: Analyze KNO3 (Potassium Nitrate)
- **Electrolysis Reaction**:
- At the cathode, water is again reduced to form hydroxide ions (OH⁻) and hydrogen gas (H₂).
- At the anode, water is oxidized to produce oxygen gas (O₂) and hydrogen ions (H⁺).
- **Result**: The hydroxide ions (OH⁻) produced at the cathode will neutralize the hydrogen ions (H⁺) produced at the anode, resulting in a neutral solution (pH = 7).

### Step 3: Analyze NaCl (Sodium Chloride)
- **Electrolysis Reaction**:
- At the cathode, water is reduced to form hydroxide ions (OH⁻) and hydrogen gas (H₂).
- At the anode, chloride ions (Cl⁻) are oxidized to produce chlorine gas (Cl₂).
- **Result**: The production of hydroxide ions makes the solution basic.

### Step 4: Analyze LiF (Lithium Fluoride)
- **Electrolysis Reaction**:
- At the cathode, water is reduced to form hydroxide ions (OH⁻) and hydrogen gas (H₂).
- At the anode, water is oxidized to produce oxygen gas (O₂) and hydrogen ions (H⁺).
- **Result**: The hydroxide ions (OH⁻) produced at the cathode will neutralize the hydrogen ions (H⁺) produced at the anode, resulting in a neutral solution (pH = 7).

### Conclusion
From the analysis:
- **CH3COONa** and **NaCl** remain alkaline after electrolysis due to the production of hydroxide ions.
- **KNO3** and **LiF** result in neutral solutions after electrolysis.

### Final Answer
The aqueous solutions that remain alkaline after electrolysis are:
- **CH3COONa (Sodium Acetate)**
- **NaCl (Sodium Chloride)**