In the reaction.
`H_(2)S+H_(2)O_(2) rarr S+2H_(2)O` describes
1. Acidic nature of `H_(2)O_(2)`
2. Reducing nature of `H_(2)O_(2)`
3. Alkaline nature of `H_(2)O_(2)`
4. Oxidizing nature of `H_(2)O_(2)`

Explanation

To solve the question regarding the reaction between \( H_2S \) and \( H_2O_2 \) to form sulfur and water, we need to analyze the roles of \( H_2S \) and \( H_2O_2 \) in the reaction.

### Step-by-Step Solution:

1. **Identify the Reaction**: The reaction given is:
\[ H_2S + H_2O_2 \rightarrow S + 2H_2O \]
Here, \( H_2S \) (hydrogen sulfide) reacts with \( H_2O_2 \) (hydrogen peroxide) to produce sulfur and water.

**Hint**: Look at the reactants and products to understand what is being oxidized and reduced.

2. **Determine Oxidation States**:
- In \( H_2S \), sulfur has an oxidation state of \(-2\).
- In \( H_2O_2 \), the oxidation state of oxygen is \(-1\).
- In the product \( S \), sulfur has an oxidation state of \(0\).
- In \( H_2O \), oxygen has an oxidation state of \(-2\).

**Hint**: Assign oxidation states to each element in the reactants and products to identify changes.

3. **Identify Oxidation and Reduction**:
- \( H_2S \) is oxidized to sulfur (oxidation state changes from \(-2\) to \(0\)).
- \( H_2O_2 \) is reduced (as it gains electrons) to water (oxidation state of oxygen changes from \(-1\) to \(-2\)).

**Hint**: Remember that oxidation involves loss of electrons, while reduction involves gain of electrons.

4. **Identify the Reducing and Oxidizing Agents**:
- \( H_2S \) acts as the reducing agent because it donates electrons (is oxidized).
- \( H_2O_2 \) acts as the oxidizing agent because it accepts electrons (is reduced).

**Hint**: The substance that gets oxidized is the reducing agent, and the one that gets reduced is the oxidizing agent.

5. **Evaluate the Options**:
- **Acidic nature of \( H_2O_2 \)**: Not correct, as the reaction does not demonstrate acidity.
- **Reducing nature of \( H_2O_2 \)**: Not correct, as \( H_2O_2 \) is not acting as a reducing agent here.
- **Alkaline nature of \( H_2O_2 \)**: Not correct, as the reaction does not indicate basicity.
- **Oxidizing nature of \( H_2O_2 \)**: Correct, since \( H_2O_2 \) is acting as an oxidizing agent.

**Hint**: Analyze each option based on the roles of the reactants in the reaction.

### Conclusion:
The correct answer is **4. Oxidizing nature of \( H_2O_2 \)**.