Strong reducing behaviour of `H_3 PO_2` is due to

Options

A. Presence of one -OH group and two P - H bonds
B. High electron gain enthalpy of phosphorus
C. High oxidation state of phosphorus
D. Presence of two -OH groups and one P - H bond

Explanation

To understand the strong reducing behavior of H₃PO₂ (phosphorous acid), we can analyze its structure and the nature of its bonds step by step.

### Step-by-Step Solution:

1. **Identify the Structure of H₃PO₂**:
- H₃PO₂ consists of phosphorus (P) bonded to three hydrogen atoms (H) and one hydroxyl group (OH).
- The structural formula can be represented as:
```
H
|
H - P = O
|
OH
```

2. **Analyze the Bonds in H₃PO₂**:
- In H₃PO₂, there are:
- One P=O (double bond)
- One P-OH (single bond)
- Two P-H (single bonds)
- The presence of these bonds is crucial for understanding its reducing properties.

3. **Understanding Reducing Behavior**:
- A reducing agent is a substance that donates electrons in a chemical reaction, thereby reducing another substance.
- The P-H bonds in H₃PO₂ are particularly important because they can easily donate electrons.

4. **Role of P-H Bonds**:
- The two P-H bonds in H₃PO₂ are responsible for its strong reducing nature.
- The ability of these bonds to release hydrogen ions (H⁺) contributes to the reducing capacity of the compound.

5. **Conclusion**:
- The strong reducing behavior of H₃PO₂ is primarily due to the presence of two P-H bonds, which facilitate the donation of electrons.

### Final Answer:
The strong reducing behavior of H₃PO₂ is due to the presence of two P-H bonds.

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