`H_3 PO_3` has ……non ionisable P-H bonds

Options

A. None
B. 1
C. 2
D. 3

Explanation

To determine the number of non-ionizable P-H bonds in H₃PO₃ (phosphorous acid), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure of H₃PO₃**:
- H₃PO₃ has a phosphorus (P) atom at the center.
- It has one double bond with an oxygen (O) atom.
- The phosphorus atom is also bonded to three hydrogen (H) atoms and two other oxygen atoms.

2. **Draw the Lewis Structure**:
- The Lewis structure of H₃PO₃ can be represented as:
```
O
||
H - P - O - H
|
H
```
- In this structure, one oxygen is double-bonded to phosphorus, while the other two oxygens are single-bonded to phosphorus, with one of them bonded to a hydrogen atom.

3. **Identify the Types of P-H Bonds**:
- The P-H bonds can be classified as ionizable or non-ionizable.
- Ionizable P-H bonds are those where the hydrogen is directly bonded to an electronegative atom (like oxygen), allowing it to release a proton (H⁺) in solution.
- Non-ionizable P-H bonds are those where the hydrogen is bonded to phosphorus directly without being influenced by electronegative atoms.

4. **Count the Ionizable and Non-Ionizable P-H Bonds**:
- In H₃PO₃, there are two types of hydrogen:
- One hydrogen is bonded to an oxygen atom (O-H), which is ionizable.
- The other two hydrogens are directly bonded to phosphorus (P-H), which are non-ionizable.
- Therefore, there are **two ionizable** and **one non-ionizable** P-H bond.

5. **Conclusion**:
- The number of non-ionizable P-H bonds in H₃PO₃ is **1**.

### Final Answer:
H₃PO₃ has **1** non-ionizable P-H bond.

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