In Hall process, in the production of Al, carbon is used as the anode material . The reaction are :

Options

A. Anode : `Al^(3+) + 3e^(-)rightarrow Al`
cathod:
`C(s)+ 2O^(2-) rightarrow CO_(2) (g)+ 4e^(-)`
B. Anode: `C_(s)+O_(2)rightarrow CO_(2)`
Cathod : `Al^(3+) + 3e^(-)rightarrowAl`
C. Anode : `Alrightarrow Al^(3+)+e^(-)`
Cathod : `Co_(2)+4e^(-)rightarrow C(s) + 2o^2-)`
D. None of above

Explanation

To solve the question regarding the Hall process for the production of aluminum, we will analyze the reactions that occur during the electrolysis of aluminum oxide (Al₂O₃) using carbon as the anode material.

### Step-by-Step Solution:

1. **Understanding the Hall Process**:
The Hall process involves the electrolysis of aluminum oxide (Al₂O₃) dissolved in molten cryolite (Na₃AlF₆). The cryolite lowers the melting point of the aluminum oxide and increases its conductivity.

2. **Reactions at the Cathode**:
At the cathode, aluminum ions (Al³⁺) gain electrons to form molten aluminum (Al). The half-reaction can be written as:
\[ \text{Al}^{3+} + 3e^- \rightarrow \text{Al (l)} \]

3. **Reactions at the Anode**:
At the anode, oxide ions (O²⁻) lose electrons to form oxygen gas (O₂) and carbon dioxide (CO₂) from the reaction with carbon (graphite). The half-reaction can be written as:
\[ 2\text{O}^{2-} \rightarrow \text{O}_2(g) + 4e^- \]
The overall reaction at the anode can be summarized as:
\[ \text{C (s)} + \text{O}_2^- \rightarrow \text{CO}_2(g) + 4e^- \]

4. **Overall Reaction**:
Combining the half-reactions from the cathode and anode, the overall reaction for the Hall process can be expressed as:
\[ \text{Al}_2\text{O}_3 + 3\text{C} \rightarrow 4\text{Al (l)} + 3\text{CO}_2(g) \]

5. **Balancing the Equation**:
The balanced equation shows that for every mole of aluminum oxide, three moles of carbon are consumed to produce four moles of aluminum and three moles of carbon dioxide.

6. **Conclusion**:
The reactions occurring in the Hall process involve the reduction of aluminum ions at the cathode and the oxidation of oxide ions at the anode, resulting in the production of aluminum and carbon dioxide.

### Final Answer:
None of the provided options in the question are correct regarding the reactions occurring in the Hall process.