What is the half-life for a second-order reaction?

Question

Quizplus · Accepted Answer

The half-life for a second-order reaction is given by the equation:

t1/2 = 1 / k[A]0

where t1/2 is the half-life, k is the rate constant, and [A]0 is the initial concentration of the reactant.

For a second-order reaction, the rate law is:

rate = k[A]^2

Thus, the rate constant for a second-order reaction is given by:

k = rate / [A]^2

Substituting this expression for k into the equation for the half-life, we get:

t1/2 = 1 / (rate / [A]^2)[A]0

Simplifying, we get:

t1/2 = [A]^2 / rate[A]0

Thus, the half-life for a second-order reaction depends on the initial concentration of the reactant and the rate of the reaction. It is not a constant value. Therefore, none of the answer choices is valid.

What Is the Half-Life for a Second-Order Reaction