In a second order reaction:
I.the sum of the exponents in the rate law is equal to two.
II.at least one of the exponents in the rate law is a two.
III.the half-life is dependent on the initial concentration of the reactant species.
IV.the half-life is independent of the initial concentration of the reactant species.
V.k can be expressed as M^-2s^-1 or M^-2min^-1.

Question

Quizplus · Accepted Answer

In a second order reaction, the sum of the exponents in the rate law is two (I). Also, the half-life is dependent on the initial concentration of the reactant (III), which means that the reaction rate is directly proportional to the initial concentration of the reactant. The half-life expression for a second-order reaction is t1/2 = 1/(k[A]0) and is inversely proportional to the initial concentration of the reactant. Therefore, the half-life is not independent of the initial concentration of the reactant (IV). Option II is incorrect because the exponents in a second-order reaction can be any combination of 1 and 2. Option V is also incorrect because the correct expression for the rate constant k in a second-order reaction is k=[A]0 / (t1/2) or k=1/(t1/2)[A]0, which can be simplified to k = 1/t[A]0.

In a Second Order Reaction