Term: bond enthalpy
https://doi.org/10.1351/goldbook.08147

Definition:
Average value of the gas-phase bond-dissociation enthalpies (usually at a temperature of \(\pu{298 K}\)) for all bonds of the same type within the same chemical species.

Note: More commonly, tabulated mean bond energies (which are really enthalpies) are values of bond enthalpies averaged over a number of selected chemical species containing that type of bond, such as \(\pu{414 kJ mol-1}\) for \(\ce{C-H}\) bonds in a group of \(\ce{R3CH}\) (\(\ce{R = H}\), alkyl).

Example: For methane, the mean bond enthalpy is <span title="numeric value with unit">\(\pu{415.9 kJ mol-1}\)</span>, one-fourth the enthalpy of reaction for <span title="reaction">\[\ce{CH4 (g) -> C (g) + 4H (g)}\]</span>

Example: Array

Link: 
Related Term: bond-dissociation enthalpies (http://doi.org/10.1351/goldbook.08146).

Source: PAC, 2022, 94, 353. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)' on page 372 (https://doi.org/10.1515/pac-2018-1010)

Citation: 'bond enthalpy' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.08147

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