Question

Identify molecularity and write the rate law for the following elementary reaction. NO(g) + O3(g) = NO3(g) + O(g)
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Answer 1

The Molecularity of the given reaction is 2.

The Rate law for the reaction is-  R = k [NO]¹ [O₃]¹

• The Molecularity of a reaction is defined as the number of molecules of reactants participating in a reaction to form the product.
• In the given reaction, there is one molecule of NO and one molecule of O₃ are participating, hence its molecularity is two.
• The Rate law is defined as-

        rate of reaction, R ∝ concentration of reactants

        For the reaction: aA   →  B

        Rate, R = k [A]ᵃ

• Therefore, for the given reaction, the rate law is-

        Rate of reaction, R = k [NO]¹[O₃]¹

        R = k[NO] [O₃]