Which is the correct statement for the given acids ?

Options

A. Phosphinic acid is a diprotic acid while phosphonic acid is a monoprotic acid
B. Phosphinic acid is a monoprotic acid while phosphoric acid is a diprotic acid
C. Both are diprotic acids
D. Both are triprotic acids

Answer

To determine the correct statement regarding the acids mentioned in the question, we will analyze the structures and properties of phosphinic acid and phosphonic acid.

### Step-by-Step Solution:

1. **Identify the Acids**: The acids in question are phosphinic acid (H3PO2) and phosphonic acid (H3PO3).

2. **Draw the Structure of Phosphinic Acid**:
- Phosphinic acid (also known as hypophosphorous acid) has the formula H3PO2.
- Its structure can be represented as:
- A phosphorus (P) atom is double-bonded to an oxygen (O) atom.
- It has one hydroxyl group (OH) attached to the phosphorus.
- There are two hydrogen atoms (H) attached to the phosphorus.
- Therefore, the structure looks like this:
```
O
||
H-P-OH
|
H
```
- Since there is only one hydroxyl group (OH), phosphinic acid is a **monoprotic acid** (or monobasic).

3. **Draw the Structure of Phosphonic Acid**:
- Phosphonic acid (also known as orthophosphorous acid) has the formula H3PO3.
- Its structure can be represented as:
- A phosphorus (P) atom is double-bonded to an oxygen (O) atom.
- It has two hydroxyl groups (OH) attached to the phosphorus.
- There is one hydrogen atom (H) attached to the phosphorus.
- Therefore, the structure looks like this:
```
O
||
H-P-OH
|
HO
```
- Since there are two hydroxyl groups (OH), phosphonic acid is a **diprotic acid** (or dibasic).

4. **Conclusion**:
- Based on the analysis:
- Phosphinic acid is monoprotic (H3PO2).
- Phosphonic acid is diprotic (H3PO3).
- Therefore, the correct statement is: "Phosphinic acid is a monoprotic acid while phosphonic acid is a diprotic acid."

### Final Answer:
The correct statement is: **Phosphinic acid is a monoprotic acid while phosphonic acid is a diprotic acid.**