To remove the acidic impurity, the flux that can be used is

Options

A. `SiO_(2)`
B. CaO
C. NaCl
D. CuO

Answer

To solve the question regarding the flux that can be used to remove acidic impurities, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Flux**:
- Flux is a substance added during the metallurgical process to help remove impurities from ores. It reacts with impurities to form a slag that can be easily removed.

2. **Identify the Types of Flux**:
- There are two main types of flux:
- **Acidic Flux**: Used to remove basic impurities (e.g., silica, SiO2).
- **Basic Flux**: Used to remove acidic impurities (e.g., iron oxide, Fe2O3).

3. **Analyze the Given Options**:
- The options provided are:
- SiO2 (silica)
- CaO (calcium oxide)
- NaCl (sodium chloride)
- CuO (copper oxide)

4. **Determine the Nature of the Impurity**:
- Since the question specifies that we need to remove an acidic impurity, we need to use a basic flux.

5. **Identify the Basic Flux**:
- From the options, the only basic flux is **CaO (calcium oxide)**.
- Calcium oxide reacts with acidic impurities to form a slag. For example, it can react with silica (SiO2) to form calcium silicate (CaSiO3).

6. **Write the Reaction**:
- The reaction can be represented as:
\[ \text{CaO} + \text{SiO2} \rightarrow \text{CaSiO3 (slag)} \]

7. **Conclusion**:
- Therefore, the correct flux to remove the acidic impurity is **CaO**.

### Final Answer:
The flux that can be used to remove the acidic impurity is **CaO**.

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