Question:
Why is molecularity applicable only for elementary reactions and order is applicable for elementary as well as complex reactions?
Why is molecularity applicable only for elementary reactions and order is applicable for elementary as well as complex reactions?
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Molecularity → theoretical (single step); Order → experimental (any reaction).
Updated On: Jan 14, 2026
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Solution and Explanation
Molecularity is the number of molecules involved in an elementary step — it is always a whole number and theoretical.
For complex reactions, which occur in multiple steps, overall molecularity is meaningless.
Order is experimentally determined from the rate law and applies to both elementary and complex reactions because it depends on the slow step or mechanism.
For complex reactions, which occur in multiple steps, overall molecularity is meaningless.
Order is experimentally determined from the rate law and applies to both elementary and complex reactions because it depends on the slow step or mechanism.
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