### Linear versus Non-Linear

Posted:

**Sat Mar 14, 2020 2:12 pm**Hoe do you know when to use the linear first order integrated rate law (ln[A]=-kt+ln[A initial]) versus the nonlinear form ([A]=[A initial]e^-kt)?

Created by Dr. Laurence Lavelle

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

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=148&t=62460

Page **1** of **1**

Posted: **Sat Mar 14, 2020 2:12 pm**

Hoe do you know when to use the linear first order integrated rate law (ln[A]=-kt+ln[A initial]) versus the nonlinear form ([A]=[A initial]e^-kt)?

Posted: **Sat Mar 14, 2020 2:25 pm**

I find the linear form easier to use in general for solving for different variables and basically everything. The linear form is also what you use to graph: you graph lnA versus time and the slope of the line is -k. I can't think of a good use for the nonlinear equation.

Posted: **Sat Mar 14, 2020 2:28 pm**

The linear form is useful for graphical analysis and basic comprehension. It can also be useful for finding k, because its the slope of the line. Either work for simple calculation using the relationship between time and concentration of the reactant.

Posted: **Sat Mar 14, 2020 4:15 pm**

Would there ever be a first order linear slope that is positive and not negative?