How long will it take for the concentration of A to decrease from 1.400 M to 0.643 for the zero order reaction A → Products? (k = 0.0345 M/s)

Question

How long will it take for the concentration of A to decrease from 1.400 M to 0.643 for the zero order reaction A → Products? (k = 0.0345 M/s)



Answer 1

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

[A] = 0.643 M

[A]_o = 1.400 M

k = 0.0345 M/s

t = ?

0.643 M = 1.400 M - 0.0345 M/s t

t = 21.9 seconds

Answer 2

0th order reaction means that the rate does not depend on C_A or r_A = -k

C_A = C_A0 - kt Plug in the values and solve for time.