1. The Arrhenius equation

2. T = temperature in kelvin
Exponential form
R = gas constant = J K–1 mol–1
T = temperature in kelvin
Exponential factor, e–Ea/RT: proportion of molecules that have sufficient energy for a reaction to take place
Pre-exponential term (frequency factor), A, accounts for the frequency of collisions with the correct orientation

3. intercept on the y-axis, c = ln A.
Logarithmic form
A plot of ln k against 1/T gives a downward straight line graph of the type y = mx + c
gradient m = –Ea/R
intercept on the y-axis, c = ln A.

4. Graph of ln k against 1/T

5. Ea from an Arrhenius plot