(a) Define order of reaction. How does order of a reaction differ from molecularity for a complex reaction?
(b) A first-order reaction is complete in 25 minutes. Calculate the time for
completion of the reaction.
(a) Order of a Reaction: The sum of the power of the concentration of the reactants in the rate law expression is known as the order of the reaction
Consider the general reaction
Where x is order w.r.t A and Y is order w.r.t B
Overall order
Order of Reaction | Molecularity |
(1) It is the sum of the concentration terms on which the rate of reaction actually depends. (2) It can be fractional as well as zero. |
(1) It is the number of atom ions or molecules that must collide with one another simultaneously so as to result into a chemical reaction. (2) It is always a whole number. It cannot be zero or fractional. |
(b) For a first-order reaction :
Now, using the first-order reaction,