1. Tardigrade
  2. Question
  3. Chemistry
  4. The molecularity of a reaction is :

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The molecularity of a reaction is :

AFMCAFMC 2001

Solution:

The number of reacting species (atoms, ions or molecules) which must collide simultaneously in order to bring about the chemical reaction is called molecularity of reaction. It is always a natural number $(1,2,3$ etc. $)$
Order of a reaction is the sum of the powers of concentration terms in the rate law. It is determined experimentally and can have zero and fractional value also. Molecularity and order of reaction for any given reaction may be same or different.
$2HI \xrightarrow{\text{Air}} H_2 + I_2$
order $ =0$, molecularity $ =2$
$2NO + O_2 \rightarrow 2NO_2$,
order $ = 3$, molecularity $ = 3$