For Gibbs energy, we have 'exergonic' or 'endergonic'

For Enthalpy, we have 'exothermic' or 'endothermic'

It seems logical there should be an equivalent pair of terms for entropy, but I can't seem to find them. Any help would be appreciated; if I'm just blind and haven't seen the terms apologies!

  • $\begingroup$ Hmm, not sure if I have ever heard any. Only informal ones come to mind, related to the order level. $\endgroup$
    – Poutnik
    Commented Jul 9, 2022 at 4:49
  • $\begingroup$ Curious - I feel like such terms would be very useful in describing reactions. $\endgroup$
    – tgsweat
    Commented Jul 9, 2022 at 5:01
  • $\begingroup$ Exothermic or endothermic does not refer to whether a process is "favourable", only the direction of heat transfer, which in a process at constant T and p corresponds to the enthalpy change. The Gibbs energy change actually describes whether the total entropy (system plus surroundings) increases or decreases for a process at constant T and p. $\endgroup$
    – Buck Thorn
    Commented Jul 9, 2022 at 12:42
  • $\begingroup$ but does not direction of heat transfer indicate how thermodynamically favourable it is? surely reactions tend towards products with lower thermodynamic energy (if entropy is roughly the same on both sides) - since they would be more stable? $\endgroup$
    – tgsweat
    Commented Jul 10, 2022 at 3:40
  • $\begingroup$ Yes but "tend" is a key word. Perhaps I am nitpicking but it's important that you be clear. You are looking for a word that describes whether the entropy change is positive or negative. Whether that is favourable is irrelevant. $\endgroup$
    – Buck Thorn
    Commented Jul 10, 2022 at 16:47


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.