Arrhenius Rate Constant
Arrhenius Rate Constant
The Arrhenius equation shows how reaction rate climbs with temperature, set by the activation energy.
The rate constant is k = A·e^(−E_a/(R·T)). where A is the pre-exponential factor, E_a the activation energy, R the gas constant and T temperature.
Inputs
A := 5e10=5e+10
E_a := 75000 J/mol=75000 kg·m^2/mol/s^2
R := 8.314 J/(mol·K)=8.31 kg·m^2/K/mol/s^2
T := 350 K=350 K
Apply the Arrhenius equation.
k := A·exp(-E_a/(R·T))=0.32
Results
A modest temperature rise can multiply the rate several-fold because of the exponential term — the reason heating speeds reactions and cooling preserves food.
Assumptions & limitations
- Single elementary step.
- Temperature-independent A and E_a.
- Absolute temperature.