Equations · Chemistry and biology
Arrhenius equation
How a reaction's rate constant rises with temperature.
k = A e^(−Eₐ / (RT))
Aethel says
k equals A e to the power of negative E sub a over the quantity R T
What it says
Only molecules with at least the activation energy react, and the fraction that have it grows exponentially with temperature. A modest warming can therefore speed a reaction up many times over.
Symbol by symbol
| Symbol | Say it | Means |
|---|---|---|
| k | k | the rate constant |
| A | A | the pre-exponential factor |
| Eₐ | E sub a | the activation energy |
| R | R | the gas constant |
| T | T | the absolute temperature, in kelvin |
Where you meet it
Chemical kinetics, materials science and food science.
Questions
How do you say Arrhenius equation out loud?
k = A e^(−Eₐ / (RT)) is read: “k equals A e to the power of negative E sub a over the quantity R T.” That is exactly what Aethel says when it meets the formula in a book.
What does k mean in Arrhenius equation?
k (said “k”) is the rate constant.
What does A mean in Arrhenius equation?
A (said “A”) is the pre-exponential factor.
Can I listen to the equations in my own textbook like this?
Yes. Upload a PDF, EPUB or text file and Aethel reads it aloud with every equation spoken as maths, the way it reads this one, and highlights each sentence as it goes. You can start free.