In the electrolysis of aqueous sodium chloride solution which of the hall cell reaction will occur at anode?

Options

A. `Na_((aq))^(+) + e^(-) to Na_((s)) , E_"cell"^@`=-2.71 V
B. `2H_2O_((l)) to O_(2(g)) + 4H_((aq))^(+) + 4e^(-) , E_"cell"^@`=1.23 V
C. `H_((aq))^(+) + e^(-) to 1/2H_(2(g)) , E_"cell"^@` =0.00 V
D. `Cl_((aq))^(-) to 1/2Cl_(2(g)) + e^(-) ,E_"cell"^@` =1.36 V

Explanation

To determine which reaction occurs at the anode during the electrolysis of aqueous sodium chloride (NaCl) solution, we need to analyze the possible oxidation reactions that can take place at the anode.

### Step-by-Step Solution:

1. **Identify the Electrolysis Process**:
- In the electrolysis of aqueous sodium chloride, we have sodium ions (Na⁺), chloride ions (Cl⁻), and water (H₂O) present in the solution.

2. **Possible Oxidation Reactions at the Anode**:
- At the anode, oxidation reactions occur. The two possible reactions that can happen are:
- Reaction 1: Oxidation of chloride ions:
\[ 2Cl^- \rightarrow Cl_2(g) + 2e^- \]
- Reaction 2: Oxidation of water:
\[ 2H_2O(l) \rightarrow O_2(g) + 4H^+(aq) + 4e^- \]

3. **Standard Electrode Potentials**:
- The standard electrode potential (E°) for each reaction helps us determine which reaction is more favorable:
- For the oxidation of chloride ions:
\[ E° = +1.36 \, \text{V} \]
- For the oxidation of water:
\[ E° = +1.23 \, \text{V} \]

4. **Comparing Electrode Potentials**:
- The reaction with the lower standard electrode potential is more favorable for oxidation at the anode. Here, the oxidation of water has a lower E° value (1.23 V) compared to the oxidation of chloride ions (1.36 V).

5. **Conclusion**:
- Since the oxidation of water has a lower E° value, it is the preferred reaction at the anode during the electrolysis of aqueous sodium chloride solution.

### Final Answer:
The reaction that occurs at the anode is:
\[ 2H_2O(l) \rightarrow O_2(g) + 4H^+(aq) + 4e^- \]