Intrinsic activation energy

{
  "id": "MLC-T-CHM-006023",
  "term": "Intrinsic activation energy",
  "field": "Chemistry",
  "definition": "The smaller of the activation energies for a reaction's forward and reverse directions, which is the activation energy in the exothermic direction. If Ea(1) and Ea(-1) are the forward and reverse values, the intrinsic value is the lesser of the two, and their difference is approximately the reaction enthalpy change. In Marcus theory, a related but separate intrinsic barrier is the barrier for a thermoneutral reaction.",
  "subject": "Physical and Biophysical Chemistry",
  "see_also": [
    "activation",
    "activation energy"
  ],
  "references": [
    "PAC, 1996, 68, 149. 'A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)' on page 170 (https://doi.org/10.1351/pac199668010149)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/intrinsic-activation-energy/"
}