Question

from rxn mechanism

03+ no2 ->no3 +o2 (slow)

no3+no2->n2o5 (fast)

rate=k [o3]1 [no2]1

so here, I see that order is 1 for [o3] and [no2] because o3 + no2 has 1 coefficient in front.

but my question is I learned that the order of reaction is not equal to the coefficient of species. !!

so why coefficient is determined when writing rate of reaction here? this does not make sense to me.

Answer 1

I think you don't know what is coefficient K denotes to. Thats why you have this doubt. let me clear it

rate constant ie coefficient K is actually a proportionality constant for a given reaction. it did not depends on order of reaction. according to rate law rate of reaction is the change in concentration of reactants or products with respect to time.

ie; rate is directly propotional to concentration of reactants or product and inversely proportional to time

when changing the proportionality sign we must multiply it by a rate constant k. so in your equation

rate = K[O3][NO2].