Which of the following reactions does not take place during smelting step in carbon reduction process for extraction of Pb?

Options

A. `PbO + CO to Pb + CO_(2)`
B. `PbO + C to Pb + CO
C. `3Pbo + (1)/(2) O_(2) to Pb _(3) O_(4)`
D. CaO+SiO_(2) to CaSio_(3)

Answer

To determine which reaction does not take place during the smelting step in the carbon reduction process for the extraction of lead (Pb), we first need to understand the typical reactions that occur during this process.

### Step-by-Step Solution:

1. **Understanding Smelting**:
- Smelting is a process that involves heating ores to extract metals. In the case of lead extraction, the ore commonly used is galena (PbS).

2. **Reduction Process**:
- The carbon reduction process involves using carbon (usually in the form of coke) to reduce metal oxides or sulfides to their respective metals. For lead, the main reaction is:
\[ \text{PbS (s) + 2C (s) → Pb (l) + 2CO (g)} \]
- This reaction shows the conversion of lead sulfide (galena) into liquid lead and carbon monoxide gas.

3. **Other Possible Reactions**:
- During smelting, other reactions may also occur, such as:
- The reduction of lead oxides (if present):
\[ \text{PbO (s) + C (s) → Pb (l) + CO (g)} \]
- The formation of slag from impurities in the ore, which might involve silica and other compounds.

4. **Identifying Non-Reactions**:
- To find out which reaction does not take place during smelting, we need to look for reactions that do not involve the reduction of lead sulfide or lead oxide by carbon.
- For example, reactions involving the formation of lead carbonate (PbCO3) or reactions that do not involve lead at all would not occur during the smelting process.

5. **Conclusion**:
- Based on the typical reactions that occur during the smelting step in the carbon reduction process for the extraction of lead, any reaction that does not involve the reduction of lead sulfide or lead oxide by carbon would be the correct answer.

### Final Answer:
The reaction that does not take place during the smelting step in the carbon reduction process for extraction of Pb is one that does not involve the reduction of PbS or PbO by carbon.

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