Energy Profile Diagram
A plot of potential energy against reaction coordinate showing reactants, transition states, intermediates and products.
Unit
kJ/mol
In depth
The height of each peak above the preceding valley gives the activation energy of that step, and the overall change from start to finish gives the reaction enthalpy. Multi-step mechanisms show a peak for every step and a shallow well for each intermediate.
Examples in the real world
An SN1 profile with two humps and a carbocation well between them; a catalysed route drawn with a lower barrier.