In the extraction by electrolysis of brine. .............

Options

A. oxidation of ` Cl^(-) ` ion to chlorine gas occurs
B. reduction of ` Cl^(- ) ` ion to chlorine gas occurs
C. for overall reaction ` Delta G^(@) ` has negative value
D. a displacement reaction takes place

Explanation

**Step-by-Step Solution:**

1. **Understanding Brine:**
- Brine is an aqueous solution of sodium chloride (NaCl). It is commonly used in the electrolysis process to produce chlorine gas, hydrogen gas, and sodium hydroxide.

2. **Electrolysis Process:**
- During the electrolysis of brine, an electric current is passed through the solution. This process involves two electrodes: the anode (positive electrode) and the cathode (negative electrode).

3. **Identifying Reactions at Electrodes:**
- At the **anode**, oxidation occurs. In this case, chloride ions (Cl⁻) are oxidized to form chlorine gas (Cl₂).
- Reaction: 2 Cl⁻ (aq) → Cl₂ (g) + 2 e⁻
- At the **cathode**, reduction occurs. Water (H₂O) is reduced to form hydrogen gas (H₂) and hydroxide ions (OH⁻).
- Reaction: 2 H₂O (l) + 2 e⁻ → H₂ (g) + 2 OH⁻ (aq)

4. **Overall Reaction:**
- The overall reaction for the electrolysis of brine can be summarized as:
- 2 Cl⁻ (aq) + 2 H₂O (l) → Cl₂ (g) + H₂ (g) + 2 OH⁻ (aq)

5. **Analyzing the Options:**
- **Option 1:** Oxidation of Cl⁻ into chlorine gas occurs. (Correct)
- **Option 2:** Reduction of Cl⁻ into chlorine gas. (Incorrect, as oxidation occurs)
- **Option 3:** For the overall reaction, ΔG has a negative value. (Incorrect, ΔG is positive)
- **Option 4:** A displacement reaction takes place. (Incorrect, as no displacement occurs)

6. **Conclusion:**
- The correct option regarding the electrolysis of brine is **Option 1**: Oxidation of Cl⁻ into chlorine gas occurs.

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