Question 1

Does increasing the temperature also increase the activation energy?

Accepted Answer

No, this is a common misconception. The activation energy ($E_a$) is a fixed property for a specific reaction pathway. Increasing the temperature increases the kinetic energy of the reactant particles, meaning a greater proportion of them have enough energy to overcome the fixed $E_a$ barrier. The barrier itself does not change.

Question 2

If the peak of the Boltzmann curve is lower at a higher temperature, doesn't that mean fewer particles are reacting?

Accepted Answer

No. The peak represents the 'most probable' energy, not the total number of reactive particles. At a higher temperature, the energy distribution spreads out. While fewer particles have the 'most probable' energy, the overall average energy is higher, and crucially, a much larger proportion of particles is found at the high-energy end of the curve, beyond the activation energy. This larger number of high-energy particles is what increases the reaction rate.

Question 3

Does every collision with energy greater than the activation energy lead to a reaction?

Accepted Answer

Not necessarily. For a collision to be 'successful' or 'effective', two conditions must be met: the particles must possess energy equal to or greater than the activation energy, AND they must collide with the correct geometric orientation. Simply having enough energy is not sufficient if the particles are not correctly aligned to allow bonds to break and form.

Effect of temperature on reaction rates and the concept of activation energy

What you need to know

The Energy Hurdle for Reactions