Concept:Catalysis is classified by the physical state of the catalyst relative to the reactants. If they are in the same phase, it is homogeneous catalysis.
Formula:$$ \text{Reactants (gas)} + \text{Catalyst (gas)} \longrightarrow \text{Products} $$
Solution:- The reactants \( \text{SO}_{2} \) and \( \text{O}_{2} \) are in the gaseous phase.
- The catalyst, Nitric Oxide (\( \text{NO} \)), is also in the gaseous phase.
- Since both the catalyst and the reacting substances exist in the same phase, this is a classic example of homogeneous catalysis (Lead Chamber Process).
Why other options are incorrect:Heterogeneous catalysis requires the catalyst to be in a different phase (e.g., solid catalyst with gas reactants). Biological catalysis involves enzymes. 'Gas catalysis' is not a standard formal classification.
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