## What are the units of activation energy?

Arrhenius Equation: $\ln k = - \frac{E_{a}}{RT} + \ln A$

Harjas Sabharwal 1G
Posts: 42
Joined: Sat Jul 22, 2017 3:01 am

### What are the units of activation energy?

Do we use J/mol or J for activation energy?

Nickolas Manipud 1C
Posts: 60
Joined: Fri Sep 29, 2017 7:07 am

### Re: What are the units of activation energy?

You use J/mol.

Look at the Arrhenius equation, k = A*e^(-Ea/RT). R has units of J*K-1*mol-1 while T has units of K. The K will cancel out so what you have left is J*mol-1. You want to cancel both of these out which can be done with Ea with units of J*mol-1.

Jonathan Tangonan 1E
Posts: 50
Joined: Sat Jul 22, 2017 3:01 am

### Re: What are the units of activation energy?

You would use J/mol. The J*mol-1 cancel out with the units of the R constant which has JK-1mol-1