# Problem: Given that N2O4 is 2nd order for the reaction: N2O4 → 2 NO2, if a reaction started with 0.75 M N2O4, what is the half-time when the rate constant is 0.50 min-1 M-1 A. 1.33 minB. 2.25 minC. 0.50 minD. 2.67 minE. 10.3 min

###### FREE Expert Solution

We’re being asked to calculate the half-life of a second-order reaction with a rate constant of 0.50 min-1 M-1 initially at 0.75 M

Recall that half-life (t1/2) is the time needed for the amount of a reactant to decrease by 50% or one-half. The half-life of a second-order reaction is given by:

$\overline{){{\mathbf{t}}}_{\mathbf{1}\mathbf{/}\mathbf{2}}{\mathbf{=}}\frac{\mathbf{1}}{\mathbf{k}{\mathbf{\left[}\mathbf{A}\mathbf{\right]}}_{\mathbf{0}}}}$

where:

k = rate constant

[A]0 = initial concentration

###### Problem Details

Given that N2O4 is 2nd order for the reaction: N2O4 → 2 NO2, if a reaction started with 0.75 M N2O4, what is the half-time when the rate constant is 0.50 min-1 M-1

A. 1.33 min

B. 2.25 min

C. 0.50 min

D. 2.67 min

E. 10.3 min