Rate Constant Calculator

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Calculate the reaction rate constant (k) using the Arrhenius equation.

Arrhenius Parameters

Pre-exponential Factor (A)

Activation Energy (Ea)

J/mol

Temperature (T)

Kinetic Rate

Enter A, Ea, and T to calculate rate constant

About this calculator

Overview

The Arrhenius equation quantitatively describes how reaction rates depend on temperature. It is one of the most important concepts in chemical kinetics, explaining why even a small increase in temperature can lead to a drastic increase in the speed of a chemical reaction.

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Pro Tips

The pre-exponential factor (A) represents the frequency of collisions with the correct orientation.
Activation Energy (Ea) is the minimum energy required to trigger the reaction. Units are usually J/mol or kJ/mol.
The Universal Gas Constant (R) is approximately 8.314 J/(mol·K).
Temperature (T) MUST be in Kelvin for the math to work (K = °C + 273.15).
If you graph ln(k) vs 1/T, the result is a straight line with a slope of -Ea/R (Arrhenius Plot).

Fun Facts

"Insects like crickets chirp faster at higher temperatures because the metabolic chemical reactions driving the chirping follow the Arrhenius equation."
"Chemical light sticks (glow sticks) last longer in the freezer because the cold significantly slows down the reaction rate constant."
"Arrhenius received the Nobel Prize in 1903 for his theory of electrolytic dissociation, but his kinetics work is arguably more famous today."
"Enzymes do not change the temperature, they work by lowering the 'Ea', which can increase the rate constant 'k' by millions of times at body temperature."
"The pre-exponential factor A for gas-phase reactions is often in the range of 10¹¹ to 10¹³ L/(mol·s)."

Formula: k = A · e^(-Ea / RT)