[Bjc51192]

2H2(g) + O2 ----> 2 H2O

a) the reaction must be first order with respect to H2
B) The reaction must be second order with respect to H2
C) The reaction must be first order with respect to O2
D) both B and c must be true
E) none of the above


The answer is E

My question is how can you tell? What makes something first order in respect to H2 ext..
( im reading ahead and my dont want to burden my teacher with material that we havn't covered)

Thank You

[Schrödinger]

Order of reaction is usually experimentally determined, but for certain 'elementary' reactions order and molecularity have a direct relation. For this reaction probably, there is more to it than meets the eye. This is true with a lot of reactions. I guess you will not know for sure until you actually perform a kinetics experiment.

Sometimes, intuition helps

[Borek]

In short: reaction mechanism (so also a reaction kinetics) doesn't have to be in any way related to the overal reaction equation.