Speed of decomposition of `H_(2)O_(2)` is reduced by :

Options

A. `Na_(2)CO_(3)`
B. `NaOH`
C. Alcohol
D. Pt.

Explanation

To solve the question regarding the speed of decomposition of hydrogen peroxide (H₂O₂), we will follow these steps:

### Step-by-Step Solution:

1. **Understanding the Decomposition Reaction**:
The decomposition of hydrogen peroxide can be represented by the following chemical equation:
\[ 2 H_2O_2 \rightarrow 2 H_2O + O_2 \]
This reaction produces water and oxygen gas.

2. **Factors Affecting the Rate of Reaction**:
The speed (or rate) of a chemical reaction can be influenced by various factors such as temperature, concentration of reactants, presence of catalysts, and inhibitors.

3. **Identifying the Correct Option**:
In the context of the question, we need to determine what can reduce the speed of decomposition of H₂O₂. One common method to slow down the decomposition of hydrogen peroxide is to add certain substances.

4. **Role of Alcohol**:
Alcohols can act as stabilizing agents for hydrogen peroxide. When alcohol is added, it can help to reduce the rate of decomposition by providing an alternative reaction pathway or by stabilizing the hydrogen peroxide molecules.

5. **Conclusion**:
Based on the information, we conclude that the speed of decomposition of H₂O₂ is reduced by the presence of alcohol. Therefore, the correct option is C.

### Final Answer:
The speed of decomposition of H₂O₂ is reduced by alcohol.

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