Brine is electrolysed by using inert electrodes. The reaction at anode is

Options

A. `Cl^(-)(aq) to 1//2 Cl_2(g) + e^(-) , E_("cell")= 1.36V`
B. `2H_2O (l) to O_2(g) + 4H^(+) (aq)^(+) 4e^(-) , E_("cell") = 1.23 V`
C. `Na^(+) (aq) + e^(-) to Na(s) , E_("cell") = 2.71V`
D. `H^(+)(aq) + e^(-) to 1//2 H_2(g) , E_("cell") = 0.00V`

Explanation

To solve the question regarding the electrolysis of brine using inert electrodes and to determine the reaction at the anode, follow these steps:

### Step-by-Step Solution:

1. **Identify the Composition of Brine**:
- Brine is a concentrated solution of sodium chloride (NaCl) in water.

2. **Understand the Electrolysis Process**:
- During electrolysis, brine dissociates into its ions: Na⁺ (sodium ions) and Cl⁻ (chloride ions).

3. **Determine the Role of Electrodes**:
- Inert electrodes (like graphite or platinum) do not participate in the chemical reaction but provide a surface for the reactions to occur.

4. **Identify the Anode Reaction**:
- At the anode, oxidation occurs. The anion (Cl⁻) will migrate to the anode where it will lose electrons.

5. **Write the Half-Reaction at the Anode**:
- The oxidation of chloride ions can be represented as:
\[ 2 \text{Cl}^- \rightarrow \text{Cl}_2 + 2 \text{e}^- \]
- This shows that two chloride ions lose a total of two electrons to form one molecule of chlorine gas (Cl₂).

6. **Conclusion**:
- The reaction at the anode during the electrolysis of brine is the formation of chlorine gas (Cl₂) from chloride ions (Cl⁻) through oxidation.

### Final Answer:
The reaction at the anode during the electrolysis of brine is:
\[ 2 \text{Cl}^- \rightarrow \text{Cl}_2 + 2 \text{e}^- \]