# Problem: The reaction A =&gt; B + C is second order in A. When the initial [A] = 0.100 M, the reaction is 20.0% complete in 26.2 minutes. Calculate the value of the rate constant (in L/min·mol).a. 8.22x10-2 b. 9.54x10-2c. 1.53d. 1.05e. 0.91

###### FREE Expert Solution

We’re being asked to determine the rate constant (k) of a second-order reaction:

B + C

The concentration of A decreases by 80% (from 100% - 20% = 80%) starting 0.1 M in 26.2 minutes. 80% of 0.1 M is:

0.1 M x 0.8 = 0.08 M

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

$\overline{)\frac{\mathbf{1}}{{\mathbf{\left[}\mathbf{A}\mathbf{\right]}}_{\mathbf{t}}}{\mathbf{=}}{\mathbf{kt}}{\mathbf{+}}\frac{\mathbf{1}}{{\mathbf{\left[}\mathbf{A}\mathbf{\right]}}_{\mathbf{0}}}}$

where:

[A]t = concentration at time t

k = rate constant

t = time

[A]0 = initial concentration

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###### Problem Details

The reaction A => B + C is second order in A. When the initial [A] = 0.100 M, the reaction is 20.0% complete in 26.2 minutes. Calculate the value of the rate constant (in L/min·mol).

a. 8.22x10-2

b. 9.54x10-2

c. 1.53

d. 1.05

e. 0.91

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Integrated Rate Law concept. You can view video lessons to learn Integrated Rate Law. Or if you need more Integrated Rate Law practice, you can also practice Integrated Rate Law practice problems.

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