The activation energy of a chemical reaction can be calculated by:

1. Determining the rate constant at standard temperature.
2. Determining the rate constant at two temperatures.
3. Determining probability of collision.
4. Using the catalyst.

HINT: The formula used is In  (k1k2) = EaR [ 1T1 - 1T2]

Explanation:

The activation energy of a chemical reaction is related to the rate constant of a reaction at two different temperatures i.e., k1 and k2 respectively

In  (k1k2) = EaR [ 1T1 - 1T2]

where,

Ea= activation energy T2= higher temperature T1= lower temperature k1= rate constant at lemperature T1k2= rate constant at temperature T2

This equation is known as the Arrhenius equation.