Illustration of change in activation energy caused by a catalyst. Made by me in Inkscape by tracing the original image by Vinay.bhat, who holds the copyright but has released all rights.

Description of original image:

Activation energies Ea(X→Y) or 'Ea(Y→X)' need to be supplied to initiate the reactions X→Y or Y→X, respectively. When the catalyst is added, the activation energy decreases. However the Enthalpy change, ΔH (Thermodynamic factor) between X and Y remain constant. The image is created by me.

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• de: File:Aktivierungsenergie.svg
• es: File:Activation energy es.svg

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• Activation energy fr.svg
• Activation energy ja.svg