Aluminium is extracted in the electrolysis of :

Options

A. alumina
B. bauxite
C. molten cryolite.
D. alumina mixed with molten cryolite

Explanation

To answer the question, "Aluminium is extracted in the electrolysis of:", we can follow these steps:

### Step 1: Identify the source material for aluminium extraction
Aluminium is primarily extracted from its ore, which is bauxite. The main component of bauxite is aluminium oxide (Al2O3), also known as alumina.

**Hint:** Look for the ore that contains aluminium oxide.

### Step 2: Understand the role of cryolite
In the electrolysis process, alumina (Al2O3) is mixed with cryolite (Na3AlF6). Cryolite serves two important purposes: it lowers the melting point of the mixture and enhances the conductivity of the solution, making the electrolysis process more efficient.

**Hint:** Consider why additives like cryolite are used in electrolysis.

### Step 3: Write the overall reaction
During the electrolysis of the alumina mixed with cryolite, the following reaction occurs:
\[ \text{Al}_2\text{O}_3 + 3\text{C} \rightarrow 2\text{Al} + 3\text{CO}_2 \]
This indicates that aluminium is produced at the cathode, while carbon dioxide is released at the anode.

**Hint:** Think about the products formed during the electrolysis process.

### Step 4: Identify the electrolysis setup
The electrolysis is performed in a cell where a steel cathode and a graphite anode are used. The process is known as the Hall-Héroult process.

**Hint:** Remember the materials used for the electrodes in the electrolysis.

### Step 5: Conclude the answer
Based on the information gathered, aluminium is extracted in the electrolysis of alumina mixed with molten cryolite.

**Final Answer:** Aluminium is extracted in the electrolysis of alumina mixed with molten cryolite.

### Summary of Steps
1. Identify the source material (bauxite/alumina).
2. Understand the role of cryolite.
3. Write the overall reaction.
4. Identify the electrolysis setup (cathode and anode).
5. Conclude the answer.