Which one of the following is not the example of homogeneous catalysis :-

Options

A. Formation of `SO_(3)` in the chamber process
B. Formation of `SO_(3)` in the contact process
C. Hydrolysis of an ester in presence of acid
D. Decomposition of `KClO_(3)` in presence of `MnO_(2)`

Answer

To solve the question of which of the following is not an example of homogeneous catalysis, we need to analyze each option based on the definition of homogeneous catalysis. In homogeneous catalysis, both the reactants and the catalyst are in the same phase (either all gases or all liquids).

### Step-by-Step Solution:

1. **Understand Homogeneous Catalysis**:
- In homogeneous catalysis, the catalyst and the reactants are in the same phase (both gaseous or both liquid).

2. **Analyze Each Option**:
- **Option 1: Formation of SO3 in the Chamber Process**:
- Reactants: SO2 (g) and O2 (g)
- Catalyst: NO (g)
- Since all are in the gaseous state, this is an example of homogeneous catalysis.

- **Option 2: Formation of SO3 in the Contact Process**:
- Reactants: SO2 (g) and O2 (g)
- Catalyst: V2O5 (s) or Platinum (s)
- Here, the reactants are gases, but the catalyst is a solid. Therefore, this is an example of heterogeneous catalysis.

- **Option 3: Hydrolysis of an Ester in the Presence of Acid**:
- Reactants: Ester (liquid) and H2O (liquid)
- Catalyst: H2SO4 (liquid)
- All components are in the liquid phase, so this is an example of homogeneous catalysis.

- **Option 4: Decomposition of KClO3 in Presence of MnO2**:
- Reactants: KClO3 (s)
- Catalyst: MnO2 (s)
- Both the reactant and the catalyst are solids, which makes this an example of homogeneous catalysis.

3. **Conclusion**:
- The only option that does not represent homogeneous catalysis is **Option 2: Formation of SO3 in the Contact Process**.

### Final Answer:
The reaction that is not an example of homogeneous catalysis is **Option 2: Formation of SO3 in the Contact Process**.

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