In the commercial electrochemical process for aluminium extraction, the electrolyte used is

Options

A. `Al(OH)_(3)` in `NaOH` solution
B. An aqueous solution of `Al_(2)(SO_(4))_(3)`
C. A molten mixture of `Al_(2)O_(3)` and `Na_(3)AlF_(6)`
D. A molten mixture of `AlO(OH)` and `Al(OH)_(3)`

Explanation

To solve the question regarding the electrolyte used in the commercial electrochemical process for aluminum extraction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Process**: The extraction of aluminum is primarily done through an electrochemical process known as the Hall-Héroult process. This process involves the electrolysis of aluminum oxide (Al2O3).

2. **Identifying the Electrolyte**: In the Hall-Héroult process, aluminum oxide (Al2O3) is not used alone. It is mixed with other substances to facilitate the electrolysis process.

3. **Adding Cryolite**: One of the key components added to aluminum oxide is cryolite (Na3AlF6). Cryolite serves two main purposes: it lowers the melting point of aluminum oxide and increases its electrical conductivity.

4. **Fluorospar**: Another compound that may be mentioned is fluorospar (CaF2), which can also be used in the process, but it is not the primary electrolyte.

5. **Final Composition of Electrolyte**: The primary electrolyte used in the commercial extraction of aluminum is a molten mixture of aluminum oxide (Al2O3) and cryolite (Na3AlF6).

6. **Conclusion**: Therefore, the correct answer to the question is that the electrolyte used in the commercial electrochemical process for aluminum extraction is a molten mixture of Al2O3 and cryolite.

### Answer:
The electrolyte used in the commercial electrochemical process for aluminum extraction is a molten mixture of Al2O3 and cryolite (Na3AlF6).

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