WAEC Chemistry 2021 Paper

Concept:Activation energy is the minimum energy reactants must absorb to reach the activated complex and start the reaction.Explanation:In an energy profile diagram, the reactants start at a lower energy level.They must climb the energy barrier to form the activated complex at the peak.The vertical rise from the reactant level to the peak represents the activation energy.In the given diagram, this vertical rise is labelled as $E_A$.Therefore, the activation energy of the reaction is $E_A$.Answer:Option A: $E_A$