Which of the following is an example of heterogeneous catalysis ?

Options

A. `4NH_(3) + 5O_(2) overset(Pt)to 4NO +6H_(2)O`
B. `2SO_(2) + O_(2) overset(NO)to 2SO_(3)`
C. `CH_(3)COOCH_(3) + H_(2)O overset (HCl)to CH_(3)COOH + CH_(3)OH`
D. `C_(12)H_(22)O_(11) + H_(2)O overset(H_(2)SO_(4))to C_(6)H_(12)O_(6)+C_(6)H_(12)O_(6)`

Explanation

To determine which of the following is an example of heterogeneous catalysis, we first need to understand what heterogeneous catalysis is.

### Step-by-Step Solution:

1. **Definition of Heterogeneous Catalysis**:
Heterogeneous catalysis occurs when the catalyst is in a different phase than the reactants. This typically involves a solid catalyst and gaseous or liquid reactants.

2. **Analyze the Given Reaction**:
The reaction provided is:
\[ \text{Pt (solid)} + 4 \text{NH}_3 (gas) + 5 \text{O}_2 (gas) \rightarrow 4 \text{NO} (gas) + 6 \text{H}_2\text{O} (gas) \]
Here, platinum (Pt) is the catalyst, and it is in the solid phase, while ammonia (NH₃) and oxygen (O₂) are in the gaseous phase.

3. **Identify the Phases of Reactants and Catalysts**:
- Catalyst: Solid (Pt)
- Reactants: Gaseous (NH₃ and O₂)

4. **Conclusion**:
Since the catalyst (Pt) is in a solid phase and the reactants (NH₃ and O₂) are in a gaseous phase, this reaction is an example of heterogeneous catalysis.

### Final Answer:
The reaction involving Pt (solid) with gaseous NH₃ and O₂ is an example of heterogeneous catalysis.

---