Which one of the followings is/are an 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 the present of acid.
D. Decomposition of `KClO_(3)` in the presence on Manganese Dioxide

Answer

To determine which of the given options are examples of homogeneous catalysis, we first need to understand what homogeneous catalysis is. Homogeneous catalysis occurs when the catalyst and the reactants are in the same physical state, typically in the same phase (e.g., all gases or all liquids).

### Step-by-Step Solution:

1. **Understand Homogeneous Catalysis**:
- Homogeneous catalysis involves a catalyst that is in the same phase as the reactants. This means that if both the catalyst and the reactants are gases or liquids, it is considered homogeneous catalysis.

2. **Analyze Option A: Formation of SO3 in the Chamber Process**:
- The reaction is: \(2SO_2 + O_2 \rightarrow 2SO_3\).
- The catalyst used is nitrogen monoxide (NO), which is a gas.
- Since all reactants (SO2, O2) and the catalyst (NO) are gases, this is an example of homogeneous catalysis.

3. **Analyze Option B: Formation of SO3 in the Contact Process**:
- The reaction is: \(2SO_2 + O_2 \rightarrow 2SO_3\).
- The catalyst used is either platinum (Pt) or vanadium pentoxide (V2O5), both of which are solids.
- Since the catalyst is solid and the reactants are gases, this is an example of heterogeneous catalysis.

4. **Analyze Option C: Hydrolysis of Esters in Presence of Acid**:
- The reaction involves an ester reacting with water in the presence of an acid (like H2SO4).
- Both the acid and the ester are in liquid form.
- Since both the reactants and the catalyst (acid) are liquids, this is an example of homogeneous catalysis.

5. **Analyze Option D: Decomposition of KClO3 in Presence of Manganese Dioxide**:
- The reaction is: \(2KClO_3 \rightarrow 2KCl + 3O_2\).
- The catalyst used is manganese dioxide (MnO2), which is a solid.
- Since the catalyst is solid and the reactants (KClO3) are also solid, this is an example of heterogeneous catalysis.

### Conclusion:
- The examples of homogeneous catalysis from the options are:
- **Option A**: Formation of SO3 in the Chamber Process (Homogeneous)
- **Option C**: Hydrolysis of Esters in Presence of Acid (Homogeneous)

### Final Answer:
**A and C are examples of homogeneous catalysis.**