## When to use rate equations

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

Ryan Neis 2L
Posts: 53
Joined: Fri Sep 29, 2017 7:04 am

### When to use rate equations

How can you determine whether or not you need to use a regular rate law equation versus an integrated rate law equation when given certain values?

Nicole Anisgard Parra 2H
Posts: 39
Joined: Sat Jul 22, 2017 3:01 am

### Re: When to use rate equations

Integrated rate laws are used when describing change in concentrations over time (finding [A]t when given [A]0 and k, for example), while regular rate laws are just used when you are given concentrations and a rate and need to calculate k.

Beza Ayalew 1I
Posts: 58
Joined: Fri Sep 29, 2017 7:07 am

### Re: When to use rate equations

Is or when is a time when you would need to use both?

Silvino Jimenez 1A
Posts: 52
Joined: Fri Sep 29, 2017 7:04 am

### Re: When to use rate equations

I believe there will be cases when both will be needed to solve problems
The first step of a problem could ask for us to use regular rate laws and given concentrations and a rate and to calculate k.

This k would be used with integrated rate laws to find the change in concentrations over time.