Which of the following gives `H_(2)O_(2)` on hydrolysis ?

Options

A. `H_(2)S_(2)O_(3)`
B. `H_(2)SO_(5)`
C. `H_(2)S_(2)O_(7)`
D. `H_(2)S_(2)O_(6)`

Answer

To determine which of the given compounds produces hydrogen peroxide (H₂O₂) upon hydrolysis, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Identify the Compounds**:
The options provided are:
- Option 1: H₂S₂O₃ (Thiosulphuric acid)
- Option 2: H₂SO₅ (Peroxo monosulphuric acid)
- Option 3: H₂S₂O₇ (Pyrosulphuric acid)
- Option 4: H₂S₂O₆ (Dithionic acid)

2. **Analyze H₂S₂O₃ (Thiosulphuric Acid)**:
- Structure: S(=O)₂(OH)(SH)
- Hydrolysis: When thiosulphuric acid is hydrolyzed, it does not produce H₂O₂. Instead, it yields sulfurous acid (H₂SO₃).

3. **Analyze H₂SO₅ (Peroxo Monosulphuric Acid)**:
- Structure: H-SO₄-O-OH
- Hydrolysis: Upon hydrolysis, peroxo monosulphuric acid produces sulfuric acid (H₂SO₄) and hydrogen peroxide (H₂O₂).
- Reaction: H₂SO₅ + H₂O → H₂SO₄ + H₂O₂

4. **Analyze H₂S₂O₇ (Pyrosulphuric Acid)**:
- Structure: H₂S₂O₇ is also known as oleum.
- Hydrolysis: Hydrolysis of pyrosulphuric acid yields sulfuric acid (H₂SO₄) but does not produce H₂O₂.

5. **Analyze H₂S₂O₆ (Dithionic Acid)**:
- Structure: H₂S₂O₆
- Hydrolysis: Dithionic acid on hydrolysis produces sulfuric acid (H₂SO₄) and sulfurous acid (H₂SO₃), but not H₂O₂.

6. **Conclusion**:
- From the analysis, only H₂SO₅ (peroxo monosulphuric acid) produces hydrogen peroxide (H₂O₂) upon hydrolysis.
- Therefore, the correct answer is **Option 2: H₂SO₅**.