In the extraction of aluminium
Process `X:` employed for red bauxite to remove iron oxide (main impurity)
Process `Y:` (Serpeck's process): used for while bauxite to remove `Z` (main impurity) then,
Select correct option for the process `X` and impurity `Z`.

Options

A. X=Hall and Heroult's process and `Z=SiO_(2)`
B. X=Baeyer's process and `Z=SiO_(2)`
C. `X=Serpeck's process and Z= iron oxide
D. X=Baeyer's process and Z = iron oxide

Answer

To solve the question regarding the extraction of aluminum from bauxite, we will break down the processes involved and identify the correct options for Process X and impurity Z.

### Step-by-Step Solution:

1. **Understanding Red Bauxite**:
- Red bauxite primarily consists of aluminum oxide (Al2O3) and iron oxide (Fe2O3). The main impurity in red bauxite is Fe2O3.

2. **Identifying Process X**:
- To remove iron oxide (Fe2O3) from red bauxite, the process used is known as **Bayer's process**. This process involves leaching the bauxite with sodium hydroxide (NaOH), which selectively dissolves the aluminum oxide while leaving the iron oxide behind.

3. **Understanding White Bauxite**:
- White bauxite, on the other hand, contains aluminum oxide (Al2O3) and silicon dioxide (SiO2). The main impurity in white bauxite is SiO2.

4. **Identifying Process Y**:
- The process used to remove silicon dioxide (SiO2) from white bauxite is known as **Serpeck's process**. This process is specifically designed to purify white bauxite by eliminating SiO2.

5. **Conclusion**:
- From the above analysis, we can conclude that:
- Process X (for red bauxite) is **Bayer's process**.
- Impurity Z (in white bauxite) is **SiO2**.

### Final Answer:
- Process X: Bayer's process
- Impurity Z: SiO2

### Correct Option:
- The correct option is: **X is equals to Bayer's process and Z is equals to SiO2.**