Which one is wrong if electrolysis of `CH_(3)COONa(aq)` is made using `Pt` electrodes ?

Options

A. `pH` of solution increases.
B. Molar ratio of gases at anode and cathode is `3:1`
C. `[CH_(3)COO^(c-)]` in solution decreases.
D. The molar ratio of gases at anode and cathode is `2:1`

Explanation

To determine which statement is wrong regarding the electrolysis of sodium acetate (CH₃COONa) using platinum electrodes, we can analyze the electrochemical reactions occurring at the anode and cathode during the process.

### Step-by-Step Solution:

1. **Identify the Electrolyte and Electrodes**:
- The electrolyte is sodium acetate (CH₃COONa) in aqueous solution.
- The electrodes used are platinum (Pt).

2. **Electrolysis Process**:
- During electrolysis, oxidation occurs at the anode and reduction occurs at the cathode.

3. **Oxidation Reaction at the Anode**:
- The acetate ion (CH₃COO⁻) is oxidized at the anode. The reaction can be represented as:
\[ 2 \text{CH}_3\text{COO}^- \rightarrow 2 \text{CO}_2 + \text{C}_2\text{H}_6 + 2 \text{e}^- \]
- This indicates that for every 2 moles of acetate ions, 2 moles of CO₂ and 1 mole of ethane (C₂H₆) are produced.

4. **Reduction Reaction at the Cathode**:
- At the cathode, hydrogen ions (H⁺) from the water are reduced to form hydrogen gas (H₂):
\[ 2 \text{H}^+ + 2 \text{e}^- \rightarrow \text{H}_2 \]

5. **Gas Production**:
- From the anode reaction, we produce 3 moles of gas (2 moles of CO₂ and 1 mole of C₂H₆).
- From the cathode reaction, we produce 1 mole of H₂ gas.

6. **Molar Ratio of Gases**:
- The molar ratio of gases produced at the anode to the cathode is:
\[ \text{Anode: 3 moles (2 CO₂ + 1 C₂H₆) : Cathode: 1 mole (H₂)} \Rightarrow 3:1 \]

7. **Analysis of Statements**:
- **Statement A**: Correct - The oxidation of acetate ions produces CO₂ and ethane.
- **Statement B**: Correct - The molar ratio of gases at the anode to cathode is indeed 3:1.
- **Statement C**: Correct - The concentration of acetate ions will decrease due to oxidation.
- **Statement D**: Incorrect - The molar ratio of gases at the anode and cathode is not 2:1; it is 3:1.

### Conclusion:
The wrong statement is that the molar ratio of gases at the anode and cathode is 2:1. The correct ratio is 3:1.