The kinetics of a gas phase reaction of the form A → Products results in a rate constant of 0.00781 M/min. For this reaction, the initial concentration of A is 0.501 M.

Question

What is the order of the reaction? - Zero order

How many minutes will it take for the concentration of A to reach 0.144 M

What will the concentration of A be after 4.25 minutes?

What is the half-life for this reaction?

Answer 1

Integrated rate equation for zero order reaction is [A] = [A]_o - kt

[0.144] = 0.501 - (0.00781)(t)

-0.357 = - 0.00781 t

t = 45.7 min

After 4.25 min:

[A] = [A]_o -kt

[A] = 0.501 - (0.00781)(4.25)

[A] = 0.468 M

Half life of a 0 order reaction is given by t_1/2 = [A]_o/2k

t/_1/2 = 0.501 / 2(0.00781) = 0.501 / 0.01562

t_1/2 = 32.1 min