Hydrogen peroxide is obtained by the electrolysis of _________.

Options

A. water
B. sulphuric acid
C. hydrochloric acid
D. fused sodium peroxide

Explanation

To solve the question "Hydrogen peroxide is obtained by the electrolysis of _________", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Methods of Preparation**:
- Hydrogen peroxide can be prepared through various methods, including laboratory and industrial methods.

2. **Laboratory Method**:
- In the laboratory, hydrogen peroxide (H2O2) can be prepared by acidifying barium peroxide (BaO2) with sulfuric acid (H2SO4) and removing excess water. The reaction can be summarized as:
\[ \text{BaO}_2 + 8 \text{H}_2\text{O} + \text{H}_2\text{SO}_4 \rightarrow \text{H}_2\text{O}_2 + \text{BaSO}_4 + 7 \text{H}_2\text{O} \]
- However, this is not the electrolysis method.

3. **Industrial Method**:
- The industrial preparation of hydrogen peroxide involves the electrolysis of sulfuric acid (H2SO4). In this process, a concentrated solution of sulfuric acid is electrolyzed at high current density.
- The electrolysis reaction produces peroxy disulfate (H2S2O8), which is then hydrolyzed to form hydrogen peroxide:
\[ \text{HSO}_4^- \rightarrow \text{H}_2\text{S}_2\text{O}_8 + 2 \text{e}^- \]
\[ \text{H}_2\text{S}_2\text{O}_8 + \text{H}_2\text{O} \rightarrow \text{H}_2\text{O}_2 + \text{H}_2\text{SO}_4 \]

4. **Conclusion**:
- Therefore, hydrogen peroxide is obtained by the electrolysis of sulfuric acid (H2SO4).

### Final Answer:
Hydrogen peroxide is obtained by the electrolysis of **sulfuric acid (H2SO4)**.

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