The second reaction in the formation of sulfuric acid occurs slowly. 2 upper S upper O subscript 2 (g) plus upper O subscript 2 (g) right arrow 2 upper S upper O subscript 3 (g).

NO2 is added to the reaction to speed it up. In which form would this substance be a homogeneous catalyst for this reaction?
NO2(g)
NO2(l)
NO2(s)
NO2(aq)

The correct option is

Explanation:

A catalyst is defined as the chemical species that increases the reaction rate but does not participate in it and is left behind after the completion.

A homogeneous catalyst is one that is present in the same phase as the reactants and products.

A heterogeneous catalyst is one that is present in different phase as that of reactants and products.

For the given chemical reaction:

As all the reactants and products are in gaseous state so, the homogeneous catalyst must also be in the gaseous state only.

Hence, the correct option is