Following reaction is an example of
`4NH_(3)(g)+50_(2)(g)overset(Pt(s)) (rarr) 4NO(g) + 6H_(2) O (g)`

Options

A. Homogeneous catalysis
B. Heterogeneous catalysis
C. Enzyme catalysis
D. Peptization

Answer

To determine the type of catalysis in the reaction

\[ 4NH_3(g) + 5O_2(g) \overset{Pt(s)}{\rightarrow} 4NO(g) + 6H_2O(g) \]

we need to analyze the components involved in the reaction.

### Step-by-Step Solution:

1. **Identify the Reactants and Products**:
- The reactants are ammonia (NH₃) and oxygen (O₂), both in the gaseous state.
- The products are nitric oxide (NO) and water (H₂O), which are also in the gaseous state.

2. **Identify the Catalyst**:
- The catalyst used in this reaction is platinum (Pt), which is in solid state.

3. **Determine the Physical States**:
- Reactants: NH₃ (g) and O₂ (g) - both are gases.
- Catalyst: Pt (s) - solid.
- Products: NO (g) and H₂O (g) - both are gases.

4. **Analyze the Relationship Between Reactants and Catalyst**:
- Since the catalyst (Pt) is in a different physical state (solid) than the reactants (gases), this indicates a specific type of catalysis.

5. **Classify the Type of Catalysis**:
- When the catalyst and the reactants are in different phases, it is classified as **heterogeneous catalysis**.
- Conversely, if the catalyst and reactants were in the same phase (both gases or both liquids), it would be classified as homogeneous catalysis.

6. **Conclusion**:
- Therefore, the given reaction is an example of **heterogeneous catalysis**.

### Final Answer:
The reaction is an example of **heterogeneous catalysis**.

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