Activation Energy Chemistry Example 1

Follow the full solution, then compare it with the other examples linked below.

Example 1

easy
Explain why a match must be struck before it ignites, even though combustion is exothermic.

Solution

  1. 1
    Combustion is exothermic overall, but it requires an initial input of energy to start — this is the activation energy (EaE_a).
  2. 2
    Striking the match provides friction-generated heat that overcomes the activation energy barrier.
  3. 3
    Once started, the exothermic reaction sustains itself by providing energy to activate neighboring molecules.

Answer

EaĀ mustĀ beĀ overcomeĀ toĀ initiateĀ theĀ reactionE_a\text{ must be overcome to initiate the reaction}
Activation energy is the minimum energy that reactant molecules must possess for a successful collision. Even highly exothermic reactions need this initial push.

About Activation Energy

The minimum kinetic energy that reactant particles must possess upon collision in order to break existing bonds and initiate a chemical reaction, represented as the.

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