Which of the following pair of ores can not be converted into corresponding metals by pyrometallurgy ?

Options

A. `Ag_(2)S,ZnS`
B. `Cu_(2)S,HgS`
C. `MnO_(2),SnO_(2)`
D. None of these

Answer

To determine which pair of ores cannot be converted into corresponding metals by pyrometallurgy, we need to analyze each option based on the principles of pyrometallurgy.

### Step-by-Step Solution:

1. **Understanding Pyrometallurgy**:
- Pyrometallurgy is a branch of metallurgy that involves the extraction and purification of metals through the application of heat. This process typically includes roasting, smelting, and refining.

2. **Analyzing the Options**:
- **Option 1: Silver Sulphide and Zinc Sulphide**:
- Silver Sulphide (Ag₂S) when heated in the presence of oxygen does not yield metallic silver (Ag) but rather forms silver sulfate (Ag₂SO₄).
- Zinc Sulphide (ZnS) similarly, when heated, forms zinc sulfate (ZnSO₄) instead of metallic zinc (Zn).
- Therefore, this pair cannot be converted into their corresponding metals by pyrometallurgy.

- **Option 2: Copper Sulphide and Mercury Sulphide**:
- Copper Sulphide (Cu₂S) can be converted to copper metal (Cu) through roasting.
- Mercury Sulphide (HgS) can also yield mercury (Hg) when subjected to heat.
- Thus, this pair can be converted into their corresponding metals.

- **Option 3: Manganese Oxide and Tin Oxide**:
- Manganese Oxide (MnO) can be reduced to manganese (Mn) using carbon at high temperatures.
- Tin Oxide (SnO₂) can also be reduced to tin (Sn) through pyrometallurgical methods.
- Therefore, this pair can also be converted into their corresponding metals.

- **Option 4: None of these**:
- This option suggests that all pairs can be converted, but we have already established that the first pair cannot be converted.

3. **Conclusion**:
- The pair of ores that cannot be converted into corresponding metals by pyrometallurgy is **Silver Sulphide and Zinc Sulphide**.

### Final Answer:
The correct answer is **Option 1: Silver Sulphide and Zinc Sulphide**.