Question

For the one step reaction

X → products

Successive half-lives are observed to be 1.88 s, 3.76 s and 7.52 s for an experiment in which [X]₀ = 1.3 M.
a. What is the order of the reaction?
(enter 0,1,2 etc)
This reactions is  order.

b. What is the value for k, the rate constant?

k =

c. Calculate the [X] at 1.9 s

[X] at 1.9 s =

Please show work/reasoning

Answer 1

a) when the half life are doubled , the order of the reaction is second order.

for second order reaction, the half life is twice as long as life span of the one before.

the order of the reaction is 2.

b)

[X]0 = 1.3M

t1/2= 1.88 s

for second order reaction

t/12 = 1/k [X]0

K = 1/t1/2*[X]0

K = 1/1.88x1.3=0.409 M-1s-1

c) at 1.9s

for second order reaction

1/[X] = 1/[X]0 + Kt

         = 1/1.3 + ( 0.409)(1.9)

1/[X] = 1.546

[X] =0.647 M