Which of the following is an example of homogeneous catalysis?

Options

A. Oxidation of `NH_3` in Ostwald's process
B. Oxidation of `SO_2` in Contact process
C. Oxidation of `SO_2` in lead chamber process
D. Manufacture of `NH_3` by Haber's process

Explanation

To determine which of the following is an example of homogeneous catalysis, we need to understand the definition of homogeneous catalysis. A homogeneous catalyst is one that exists in the same phase (solid, liquid, or gas) as the reactants in a chemical reaction.

Let's analyze the options provided in the question step by step:

1. **Oxidation of NH3 in the Oswald Process**:
- The reaction can be represented as:
\[ \text{NH}_3(g) + \text{O}_2(g) \xrightarrow{\text{Pt (s)}} \text{NO}(g) + \text{H}_2\text{O}(g) \]
- In this reaction, ammonia (NH3) and oxygen (O2) are in the gaseous state, while platinum (Pt) is a solid catalyst. Since the catalyst is in a different phase from the reactants, this is an example of heterogeneous catalysis.
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