English

Noun

exoergicity ‎(uncountable)

1. (chemistry, physics) The difference in bond dissociation energies of a reaction, symbol ΔE₀, such that energy is released.
   • 1933: The Journal of Chemical Physics, published by the American Institute of Physics

     The collision exoergicity Q is defined by Q=E'–E, the final minus initial relative kinetic energies.

   • 1981: S. J. Buelow, D. R. Wornsnop, and D. R. Herschbach, Chemistry Department, Harvard University, Cambridge, Massachusetts, Generation of “bastard” molecular ions from van der Waals clusters: Ar_n(C₂Cl₄)_m⁺ ions, suspected interlopers in collections of solar neutrinos (published in the Proceedings of the National Academy of Sciences of the United States of America, volume 78, № 12; December, 1981)

     This is probably due to dissociation induced by the large exoergicity from charge transfer between species that differ greatly in ionization potential.

   • 1985: Rodney J. Bartlett, ed, Comparison of Ab Initio Quantum Chemistry With Experiment for Small Molecules

     For the reaction exoergicity the Davidson correction has little effect. There is also a problem with the theoretical description of the kinetics of the addition reaction. A Lindemann-Hinshelwood mechanism is typically used to ...

   • 1990: Alfred L. Yergey, Liquid Chromatography / Mass Spectrometry: Techniques and Applications

     The extent of fragmentation is determined by the internal energy of the ions at formation, which is contributed by the exoergicity of the reaction in addition to the thermal energy available. Thus, more acidic reagents and higher temperatures tend to induce more fragmentation in the negative ion mode, while less acidic reagents tend to produce more fragmentation in the negative ion mode.

Usage notes

Exoergicity (which indicates a release of energy) and exothermicity (which indicates a release of heat) are not synonymous, although they are often confused.

Related terms

• exoergic

References

• 2005: Raphael D. Levine, Molecular Reaction Dynamics, Hebrew University of Jerusalem; Cambridge University Press, ISBN-13: 9780521842761, ISBN-10: 052184276X.