i have a basic doubt.
Isnt order of a chemical reaction determined only experimentally ?
i mean can we find order just by looking the balanced chemical eqn ?
i think it can only be found out from the eqn for elementary reactions. But i'm not sure
can someone pls explain
1Rahul you are right....this doubt i had in mind few months back
order of a chemical reaction determined experimentally only...but i have come across several Qs which ask the order of rxn just by giving the balanced reaction.But actually from there u only get the molecularity of reaction only.However order is not always equal to the molecularity of rxn.
After asking a few taechers and discussing with users i got to know there are only certain rxns whose order u should know as a fact...these rxn are available in NCERT in Chem. Kinetics
1order can only be determined by elementary reaction and not by looking at the balanced chemical equation.
13Reactions can be either of the two- Elementary or Complex.
ELementary(SIngle Step Mech.) - The balanced Eqn. gives the order.
Complex(Multi Step Mech.) - The balanced slowest step rxn gives the order.
(Why we call it "EXperimentally determined" is because we can't just predict whether the rxn is elementary or, guess its mechanism by merely lookin if not...These are stated/worked out on the basis of experimental data only.)
232A + 4B → C + D
so rate of reaction = \frac{-1d[A]}{2dt}= k [A]^{2}[B]^{4}
now multiply equation by 2
so 4A + 8B →2C + 2D
so rate of reaction =\frac{-1d[A]}{ldt}=k[A]^{m}[B]^{n}
so l , m , n = ???
pls giv reasons
106m and n will be same (i.e. 2 and 4 respectively) as they represent the orders of the reaction which is constant. (definitely correct)
even l =2 (doubt only here) (there is some confusion regarding this which was cleared by manish bhaiya)
see this
http://www.targetiit.com/iit-jee-forum/posts/kinetics-14705.html
and this
http://www.chemicalforums.com/index.php?topic=39807.msg152265#msg152265 (better discussion)
1how is the eqn written lyk this???
I think it sud be rather -d[A]/dt= k[A]2[B]4......always...
why to divide the coefficients in the rate eqn unless we compare the rates of two species as if -1/2 d[A]/dt = -1/4 dt[B]/dt.... and so on....????
plzzz say..
