Decomposition of `H_(2)O_(2)` can be slowed down by addittion of smass amount phosphoric acid which act as

Options

A. Stopper
B. Inhibitor
C. Detainer
D. Promotor

Answer

To solve the question regarding the effect of phosphoric acid on the decomposition of hydrogen peroxide (H₂O₂), we can break it down into several steps:

### Step-by-Step Solution:

1. **Understanding the Reaction**:
The decomposition of hydrogen peroxide (H₂O₂) can be represented by the following chemical equation:
\[ 2 H_2O_2 \rightarrow 2 H_2O + O_2 \]
This reaction is exothermic and can occur spontaneously, but it can be accelerated by certain catalysts.

2. **Role of Phosphoric Acid**:
When a small amount of phosphoric acid (H₃PO₄) is added to the reaction mixture, it acts as an inhibitor. An inhibitor is a substance that slows down a chemical reaction.

3. **Definition of an Inhibitor**:
An inhibitor is also referred to as a negative catalyst. Unlike a positive catalyst that speeds up a reaction by lowering the activation energy, an inhibitor increases the activation energy required for the reaction to proceed, thus slowing it down.

4. **Mechanism of Action**:
The addition of phosphoric acid does not participate in the reaction directly but interferes with the reaction pathway. It may form complexes with hydrogen peroxide or alter the reaction environment, making it less favorable for the decomposition to occur.

5. **Conclusion**:
Therefore, the correct answer to the question is that phosphoric acid acts as an **inhibitor** in the decomposition of hydrogen peroxide.

### Final Answer:
Phosphoric acid acts as an inhibitor in the decomposition of H₂O₂.

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