In which of the following metallurgy, self reduction is not possible

Options

A. `ZnStoZn`
B. `PbStoPb`
C. `Cu_(2)StoCu`
D. `HgStoHg`

Answer

To solve the question "In which of the following metallurgy, self-reduction is not possible," we can follow these steps:

### Step-by-Step Solution:

1. **Understand Self-Reduction**:
- Self-reduction is a process where a metal sulfide ore is converted into a metal by using its own sulfur content. This typically involves the reaction of the metal sulfide with limited oxygen to form a metal oxide and sulfur dioxide (SO2).

2. **Identify the Process**:
- In self-reduction, the metal sulfide (Ms) reacts with oxygen (O2) to produce metal oxide (MO) and sulfur dioxide (SO2). The remaining metal sulfide then reacts with the metal oxide to yield the pure metal and more SO2.

3. **Examples of Metals that Exhibit Self-Reduction**:
- Metals that can undergo self-reduction include:
- Lead (Pb)
- Mercury (Hg)
- Copper (Cu)

4. **Identify the Metallurgy in Question**:
- The question asks which metallurgy does not allow self-reduction. We need to analyze the options provided (though they are not listed in the question) and identify if any of them are associated with metals that do not undergo self-reduction.

5. **Conclusion**:
- Based on the understanding of self-reduction and the examples provided, we conclude that the metallurgy of Zinc sulfide (ZnS) to Zinc (Zn) does not involve self-reduction. Therefore, the answer is that self-reduction is not possible in the metallurgy of ZnS to Zn.

### Final Answer:
- The metallurgy where self-reduction is not possible is the metallurgy of Zinc sulfide (ZnS) to Zinc (Zn).

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