`H_(2)` is not widely used as the reducing agent in metallurgical process because

Options

A. Many metals react with `H_(2)` at elevated temperature forming hydrides
B. There is risk of explosion from `H_(2)` and `O_(2)` present in the air
C. Reducing power of `H_(2)` does not increase with temperature
D. Reducing power of `H_(2)` increases with temperature.

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of Reducing Agents:**
- In metallurgical processes, reducing agents are substances that donate electrons to another substance, thereby reducing it. They are crucial in extracting metals from their ores.

2. **Properties of Hydrogen as a Reducing Agent:**
- Hydrogen (H₂) can act as a reducing agent due to its ability to donate electrons. However, its effectiveness can vary based on temperature and the nature of the metal being reduced.

3. **Formation of Metal Hydrides:**
- One of the main reasons hydrogen is not widely used is that many metals react with hydrogen at elevated temperatures to form metal hydrides. This reaction can limit the availability of free hydrogen for reduction.

4. **Explosiveness of Hydrogen:**
- When hydrogen reacts with oxygen in the air, it can lead to explosive reactions. This poses a significant safety risk in industrial settings where hydrogen is used.

5. **Temperature Dependency:**
- Unlike some other reducing agents, the reducing power of hydrogen does not significantly increase with temperature. In metallurgical processes, a strong reducing agent should ideally have an increasing reducing power with temperature to effectively reduce metal oxides.

6. **Conclusion:**
- Therefore, due to the formation of metal hydrides, the explosive nature of hydrogen when mixed with oxygen, and the lack of increased reducing power with temperature, hydrogen is not widely used as a reducing agent in metallurgical processes.

**Final Answer:**
Hydrogen is not widely used as a reducing agent in metallurgical processes because:
- It forms metal hydrides with many metals at elevated temperatures.
- It poses an explosive risk when combined with oxygen in the air.
- Its reducing power does not increase with temperature, which is essential for effective reduction in metallurgy.

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