Which of the following is correct ?

Options

A. `H_(3) PO_(3)` is dibasic and reducing
B. `H_(3) PO_(3)` is dibasic and non - reducing
C. `H_(3) PO_(4)` is tribasic and reducing
D. `H_(3) PO_(3)` is tribasic and non-reducing

Answer

To determine which statement is correct regarding the compounds S3PO3 (Phosphorous Acid) and S3PO4 (Phosphoric Acid), we will analyze each option step by step.

### Step 1: Understand the Compounds
- **S3PO3** is known as Phosphorous Acid (H3PO3).
- **S3PO4** is known as Phosphoric Acid (H3PO4).

### Step 2: Determine the Basicity
- **Basicity** refers to the number of replaceable hydroxyl (OH) groups in an acid.
- For **H3PO3** (Phosphorous Acid):
- The structure shows 2 OH groups and 1 double-bonded oxygen to phosphorus.
- Therefore, it is **dibasic** (2 replaceable OH groups).

- For **H3PO4** (Phosphoric Acid):
- The structure shows 3 OH groups.
- Therefore, it is **tribasic** (3 replaceable OH groups).

### Step 3: Determine the Reducing and Oxidizing Nature
- **H3PO3** (Phosphorous Acid):
- It has hydrogen atoms directly bonded to phosphorus, which gives it reducing properties.
- Thus, it is a **reducing agent**.

- **H3PO4** (Phosphoric Acid):
- It does not have hydrogen atoms directly bonded to phosphorus.
- Therefore, it behaves as an **oxidizing agent**.

### Step 4: Analyze the Options
1. **Option 1**: S3PO3 is tribasic and reducing.
- Incorrect: S3PO3 is dibasic, not tribasic.

2. **Option 2**: S3PO3 is tribasic and non-reducing.
- Incorrect: S3PO3 is dibasic and reducing.

3. **Option 3**: S3PO4 is tribasic and reducing.
- Incorrect: S3PO4 is tribasic but not reducing; it is oxidizing.

4. **Option 4**: S3PO3 is tribasic and non-reducing.
- Incorrect: S3PO3 is dibasic and reducing.

### Conclusion
None of the provided options are correct as per the analysis. The correct statements should be:
- H3PO3 is dibasic and reducing.
- H3PO4 is tribasic and oxidizing.