Free Activation Energy Calculator

Calculate the activation energy (Ea) of a reaction from rate constants at two different temperatures using the Arrhenius equation.

K
K

Activation Energy (Ea)

40,202 J/mol

Activation Energy40.20 kJ/mol

Arrhenius Equation for Activation Energy

Formula

ln(k₂/k₁) = -(Ea/R) × (1/T₂ - 1/T₁)

Solving for Ea: Ea = -R × ln(k₂/k₁) / (1/T₂ - 1/T₁)

Where:

  • Ea = activation energy (J/mol)
  • R = 8.314 J/(mol·K)
  • k₁, k₂ = rate constants at temperatures T₁, T₂
  • T₁, T₂ = absolute temperatures (K)
  • Example Calculation

    A reaction has k₁ = 0.001 at 300 K and k₂ = 0.01 at 350 K.

    1. 01Ea = -R × ln(k₂/k₁) / (1/T₂ - 1/T₁)
    2. 02ln(0.01/0.001) = ln(10) = 2.3026
    3. 031/350 - 1/300 = 0.002857 - 0.003333 = -0.000476
    4. 04Ea = -8.314 × 2.3026 / (-0.000476)
    5. 05Ea = 40,200 J/mol = 40.2 kJ/mol

    Frequently Asked Questions

    Learn More

    Understanding Molarity

    Learn what molarity is, how to calculate it, and why it matters in chemistry. Covers moles, liters, dilution, and step-by-step examples for preparing solutions.

    Related Calculators