Chemistry - Chemical Kinetics Question with Solution | TestHub

(A) The molecularity of an elementary reaction indicates how many reactant species take part in the step. Thus in unimolecular reaction, only one molecule participates in the step and in bimolecular reaction, two molecules participate in the step.

(B) The rate law of an elementary relation can be predicted by simply seeing the stoichiometry of reaction. Thus, for the reaction $2\mathrm{A}+\mathrm{B}\to \mathrm{C}$, the rate law cannot be written as rate $=\mathrm{k}[\mathrm{A}{]}^2[\mathrm{B}]$

(C) The slowest elementary step in sequence of the reactions governs the overall rate of formation of product. This step is called rate determining step.

(D) A rate law is often derived from a proposed mechanism by imposing the steady state approximation or assuming that there is a pre-equilibrium.