Calculate Arrhenius frequency factor, rate constant, activation energy, or temperature from k, Ea, T, and A, with two-point Ea and k₂ scaling.

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Uses first-order rate units and molar activation energy. Two-temperature modes assume the same Arrhenius parameters over the interval.

Frequency Factor Formula

The following formula is used to calculate the Frequency Factor. 

FF = K / (e(- Ea / (R × T)))

Variables:

  • FF is the frequency factor, with the same units as the rate constant (s⁻¹ for this first-order model)
  • K is the reaction rate constant 
  • Ea is the molar activation energy (J/mol); R = 8.31446261815324 J/(mol·K) 
  • T is the temperature (K) 

How to Calculate Frequency Factor?

The following steps outline how to calculate the Frequency Factor.

  1. First, determine the reaction rate constant.
  2. Next, determine the molar activation energy (J/mol). 
  3. Next, determine the temperature (K). 
  4. Next, gather the formula from above = FF = K / (e^(-Ea/(R*T))).
  5. Finally, calculate the Frequency Factor.
  6. After inserting the variables and calculating the result, check your answer with the calculator above. 

Example Problem:

Use the following variables as an example problem to test your knowledge.

reaction rate constant = 148 s⁻¹

molar activation energy (J/mol) = 541

temperature (K) = 512; FF = 148 × exp[541 / (8.31446261815324 × 512)] ≈ 168.055945 s⁻¹