Activation Energy Calculator
Calculate activation energy (Ea) from two rate constants at two temperatures using the Arrhenius equation.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
Can't find what you need?
Request a ToolHow to Use the Activation Energy Calculator
Enter two rate constants (k1, k2) and their corresponding temperatures (T1, T2) in Kelvin. The calculator uses the two-point form of the Arrhenius equation: ln(k2/k1) = (Ea/R)(1/T1 - 1/T2) to solve for activation energy.
About the Activation Energy Calculator
Activation energy is a central concept in chemical kinetics. It determines how sensitive a reaction rate is to temperature changes. The Arrhenius equation provides a quantitative relationship between rate constants, temperature, and activation energy, allowing prediction of reaction rates under different conditions.
Frequently Asked Questions
What is activation energy?
Activation energy (Ea) is the minimum energy that reacting molecules must have for a reaction to occur. It represents the energy barrier between reactants and products. Higher Ea means the reaction is slower at a given temperature.
What units should I use for the rate constants?
The rate constants k1 and k2 must be in the same units. The calculation uses their ratio, so the units cancel out. Common units include 1/s for first-order reactions.
Why must temperatures be in Kelvin?
The Arrhenius equation requires absolute temperature (Kelvin). Using Celsius would give incorrect results because the equation involves ratios and reciprocals of temperature, where the zero point matters.