[AhmedEzatAlzawalaty]

the reaction is 2NO2 + F2 > 2NO2F


i think rate should be = k [NO2]^2[F2]  but in my book it is Rate = k [NO2][F2]

which one is right?

[Yggdrasil]

The stoichiometric reaction coefficients tell you the order of reaction only if the reaction is an elementary reaction.   If you are given a general reaction and you don't know the mechanism, there is no way you can know what the rate law will be.  For example, if the mechanism for your reaction is:

NO₂ + F₂ --> NO₂F + F^. (rate limiting step)
F^. + NO₂ --> NO₂F (very fast)

then the rate law will be v = k[NO₂][F₂].  Other reaction mechanisms will give other rate laws.

[AhmedEzatAlzawalaty]

u say that the rate of reaction is for the slow rate limiting step.am i right?