The following reaction is second order in [A] and the rate constant is A → B What is the initial concentration (M)of A if at 28 s the concentration of A was 0.26 M?

Question

The following reaction is second order in [A] and the rate constant is  A → B What is the initial concentration (M)of A if at 28 s the concentration of A was 0.26 M?

Quizplus · Accepted Answer

The integrated rate law for a second-order reaction is:

1/[A]t - 1/[A]0 = kt

We can rearrange this equation to solve for [A]0:

[A]0 = 1 / (kt) + [A]t

Plugging in the values we have:

k = 11ea7e7c_614a_ae35_9a0a_276f349cb6a2_TB1194_11 
t = 28 s 
[A]t = 0.26 M

[A]0 = 1 / (11ea7e7c_614a_ae35_9a0a_276f349cb6a2_TB1194_11 x 28 s) + 0.26 M

[A]0 = 0.36 M

Therefore, the initial concentration of A was 0.36 M.

The correct answer is (C).

The Following Reaction Is Second Order in [A] and the Rate