`H_2O_2` is prepared in laboratory by action of `H_2SO_4` with

Options

A. `Na_2O_2`
B. `BaO_2`
C. `BaO_2`.8`H_2O`
D. Both A and C

Answer

To solve the question about how `H_2O_2` (hydrogen peroxide) is prepared in the laboratory using `H_2SO_4` (sulfuric acid), we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
The question asks for the reactants used to prepare `H_2O_2` in the presence of `H_2SO_4`. One common laboratory method involves using barium peroxide.

2. **Write the Chemical Reaction**:
The reaction can be represented as:
\[ \text{BaO}_2 \cdot 8\text{H}_2\text{O} + \text{H}_2\text{SO}_4 \rightarrow \text{BaSO}_4 + \text{H}_2\text{O}_2 + 8\text{H}_2\text{O} \]
Here, `BaO2·8H2O` (hydrated barium peroxide) reacts with cold sulfuric acid.

3. **Identify the Products**:
From the reaction, the products formed are:
- Barium sulfate (`BaSO4`)
- Hydrogen peroxide (`H2O2`)
- Water (`H2O`)

4. **Conclusion**:
The reactant that is used in the preparation of `H_2O_2` with `H_2SO_4` is `BaO2·8H2O` (hydrated barium peroxide).

Thus, the correct answer is that `H_2O_2` is prepared in the laboratory by the action of `H_2SO_4` with `BaO2·8H2O`.

### Final Answer:
The correct option is **hydrated barium oxide (BaO2·8H2O)**.

---