The activation energy equation is typically represented by the Arrhenius equation, which relates the rate constant of a reaction to the activation energy and temperature. $$ k = A e^{-E_a / (RT)} $$ Where: • $k$ is the rate constant • $A$ is the pre-exponential factor or frequency factor • $E_a$ is the activation energy • $R$ is the universal gas constant ($8.314 \text{ J}\cdot\text{mol}^{-1}\cdot\text{K}^{-1}$) • $T$ is the absolute temperature in Kelvin The activation energy ($E_a$) can be isolated from this equation: $$ E_a = -RT \ln\left(\frac{k}{A}\right) $$ Or, more commonly, by comparing rate constants at two different temperatures: $$ \ln\left(\frac{k_2}{k_1}\right) = \frac{E_a}{R} \left(\frac{1}{T_1} - \frac{1}{T_2}\right) $$ This equation allows for the calculation of the activation energy if the rate constants at two different temperatures are known. What's next? Send 'em.