How many of the following species are related to Hall's process of purification of bauxite? White bauxite , `Na_(2)CO_(3), CO_(2)`, cryolite, red bauxite , NaOH

Answer

To determine how many of the given species are related to Hall's process of purification of bauxite, we will analyze each species in relation to the process.

### Step-by-Step Solution:

1. **Identify the Process**: Hall's process is specifically used for the purification of red bauxite (which contains Al2O3 with Fe2O3 as an impurity). It involves the use of sodium carbonate (Na2CO3) and produces sodium aluminate (NaAlO2) and carbon dioxide (CO2) as byproducts.

2. **List the Given Species**:
- White bauxite
- Sodium carbonate (Na2CO3)
- Carbon dioxide (CO2)
- Cryolite
- Red bauxite
- Sodium hydroxide (NaOH)

3. **Analyze Each Species**:
- **White Bauxite**: This is not related to Hall's process; it is purified by the Serpeck process. **(Not included)**
- **Sodium Carbonate (Na2CO3)**: This is used in Hall's process to react with red bauxite. **(Included)**
- **Carbon Dioxide (CO2)**: This is a byproduct of the reaction in Hall's process. **(Included)**
- **Cryolite**: This is a different mineral (Na3AlF6) and is not involved in Hall's process. **(Not included)**
- **Red Bauxite**: This is the ore that is purified using Hall's process. **(Included)**
- **Sodium Hydroxide (NaOH)**: This is produced in the process when NaAlO2 reacts with water. **(Included)**

4. **Count the Related Species**:
- The species related to Hall's process are:
- Sodium carbonate (Na2CO3)
- Carbon dioxide (CO2)
- Red bauxite
- Sodium hydroxide (NaOH)

Thus, there are **4 species** related to Hall's process.

### Final Answer:
**4 species are related to Hall's process of purification of bauxite.**