`S-S` bond is present in

Options

A. `H_(2) S_2 O_(7)`
B. `H_2 S_2 O_8`
C. `H_2 S_2 O_6`
D. `H_2 SO_5`

Answer

To determine which compound contains an S-S bond, we will analyze the given compounds one by one by drawing their structures.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds to analyze are H₂S₂O₇ (disulfuric acid), H₂S₂O₈ (peroxy disulfuric acid), H₂S₂O₆ (dithionic acid), and H₂SO₅ (peroxymonosulfuric acid).

2. **Draw the Structure of H₂S₂O₇**:
- Disulfuric acid has the structure:
```
O
||
S - O - S
|| ||
O O
|
H
```
- In this structure, there is no S-S bond.

3. **Draw the Structure of H₂S₂O₈**:
- Peroxy disulfuric acid has the structure:
```
O
||
S - O - O - S
|| || ||
O O O
|
H
```
- In this structure, there is also no S-S bond.

4. **Draw the Structure of H₂S₂O₆**:
- Dithionic acid has the structure:
```
O
||
S - S
|| ||
O O
|
H
```
- Here, we can see that there is an S-S bond.

5. **Draw the Structure of H₂SO₅**:
- Peroxymonosulfuric acid has the structure:
```
O
||
S - O - O
|| ||
O O
|
H
```
- In this structure, there is no S-S bond.

6. **Conclusion**: After analyzing all the structures, we find that the only compound that contains an S-S bond is H₂S₂O₆ (dithionic acid).

### Final Answer:
The compound that contains an S-S bond is **H₂S₂O₆ (dithionic acid)**.

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