In which of the following oxoacids of sulphur, S-O-O-S link is present ?

Options

A. Caro's acid
B. Marshell's acid
C. Sulphurous acid
D. None of these

Answer

To determine which oxoacid of sulfur contains the S-O-O-S link, we will analyze the structures of the given oxoacids. Let's break down the solution step by step.

### Step-by-Step Solution:

1. **Identify the Oxoacids of Sulfur**:
We need to consider the following oxoacids:
- A: Peroxy monosulfuric acid (H2SO5)
- B: Peroxy disulfuric acid (S2O8)
- C: Sulfurous acid (H2SO3)
- D: (Assuming another oxoacid, but not specified in the question)

2. **Draw the Structure of Peroxy Monosulfuric Acid (H2SO5)**:
- The structure consists of a sulfur atom bonded to two hydroxyl groups (OH) and one double-bonded oxygen (O).
- The formula does not show an S-O-O-S link.
- **Conclusion**: This acid does not contain the S-O-O-S link.

3. **Draw the Structure of Peroxy Disulfuric Acid (S2O8)**:
- The structure can be represented as:
```
O
||
S - O - O - S
||
O
```
- This structure clearly shows the S-O-O-S link.
- **Conclusion**: This acid contains the S-O-O-S link.

4. **Draw the Structure of Sulfurous Acid (H2SO3)**:
- The structure consists of a sulfur atom bonded to two hydroxyl groups (OH) and one double-bonded oxygen (O).
- The formula does not show an S-O-O-S link.
- **Conclusion**: This acid does not contain the S-O-O-S link.

5. **Final Conclusion**:
- Among the given options, only Peroxy Disulfuric Acid (S2O8) contains the S-O-O-S link.
- Therefore, the correct answer is **Option B**.