## 7B.5 7th edition

$\frac{d[R]}{dt}=-k[R]; \ln [R]=-kt + \ln [R]_{0}; t_{\frac{1}{2}}=\frac{0.693}{k}$

Gisela F Ramirez 2H
Posts: 61
Joined: Fri Sep 28, 2018 12:27 am

### 7B.5 7th edition

N2O5 decomposes by first order kinetics with a rate constant of 3.7*10^(-5) at 298K

For part a, find half life of N205 at 298K, what equation would I use?
For part c, how much time will elapse before the N2O5 concentration decreases from 0,0567 M to 0.0135 M? How would I solve this?

ThomasLai1D
Posts: 61
Joined: Fri Sep 28, 2018 12:17 am

### Re: 7B.5 7th edition

For part a, you would use the equation [A] = [A]initial e^-kt, and plug in 1/2 [A] initial for [A].
For part c, you would use the same equation, but solve for t by plugging in the values for initial and final concentration into [A]initial and [A] respectively.