Arrhenius graph - CI

Question 1

What is the Arrhenius graph used for

Answer 1

to find activation energy in KJ/mol

Question 2

How to find the activation energy using an Arrhenius graph

Answer 2

• find the gradient by drawing large triangle (watch out for powers in the axes labels)
• multiply by R (8.314)
• divide by 1000 to get a value in KJ/mol

Question 3

What are the axis labels on the Arrhenius graph

Answer 3

x-axis = 1/temperature in Kelvin
y-axis = ln k, where k is the rate constant - these values are usually negative

Question 4

What does a Arrhenius graph usually look like

Answer 4

https://chem.libretexts.org/@api/deki/files/102891/Arrhenius_Plot_1.bmp?revision=1&size=bestfit&width=417&height=331

Question 5

What is the formula for gradient in the Arrhenius graph

Answer 5

gradient = -Ea/R

Question 6

Why can we sometimes use ln rate instead of ln k

Answer 6

as rate is proportional to the rate constant k

Question 7

Why is ln (1/time) sometimes used instead of 1/time

Answer 7

as for clock reactants on 1/time is proportional to rate so ln 1/time is used

Question 8

Example table for Arrhenius graph:

Answer 8

https://wisc.pb.unizin.org/app/uploads/sites/564/h5p/content/209/images/file-5ec98b17dd7cc.png

Find 1/temp and ln k (make sure temperature is in Kelvin)