### 15.99

Posted:

**Tue Feb 21, 2017 9:46 pm**Could somebody explain why graphing the half life vs. concentration of a zero order reaction is linear but not if its second order?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=147&t=19764

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Posted: **Tue Feb 21, 2017 9:46 pm**

Could somebody explain why graphing the half life vs. concentration of a zero order reaction is linear but not if its second order?

Posted: **Tue Feb 21, 2017 10:34 pm**

For 0 order reactions, t1/2=[A]0/2k, which means t1/2 is proportional to A, which corresponds to a linear graph. For second order, however, t1/2=1/(k[A]0), which means t1/2 is proportional to 1/A - the graph of 1/x is not linear, so therefore the second order half life graph would also be nonlinear

Posted: **Tue Feb 21, 2017 10:38 pm**

For second order, half life is t = 1/k[A]initial . Therefore, t (half life) and concentration have 1/[A] relationship.

Whereas, for zero order, half life t = [A]initial/2k , which shows that t(half life) and initial concentration direct linear relationship.

Whereas, for zero order, half life t = [A]initial/2k , which shows that t(half life) and initial concentration direct linear relationship.