What is the bond energy of H-O? Wikipedia disagrees with itself:

What is the right value?

  • 6
    $\begingroup$ Look, both links are Wikipedia pages containing a table each. The table headers have superscript numbers seven $(^7$ and $^{[7]}),$ which refer to the entries from the list of references on the bottom of each page. These are the sources you should compare, not Wikipedia pages. $\endgroup$
    – andselisk
    Dec 24, 2020 at 12:23
  • 2
    $\begingroup$ Sure, but for the french wikipedia, the link is broken, so I could not compare. For english wikipedia, the link is given the same as information in english wikipedia. $\endgroup$ Dec 24, 2020 at 12:26
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    $\begingroup$ Plus 1,not really for the question that perhaps is a bit naive, but for having spotted the difference. I think this link should clarify why the pages show different values. Out of calculation, one should identify what O-H bond mean. en.m.wikipedia.org/wiki/Bond-dissociation_energy $\endgroup$
    – Alchimista
    Dec 24, 2020 at 12:31
  • 5
    $\begingroup$ thank you. Apparently, there are several values, depending on the environnement : O−H in water 497 O−H in methanol 440 $\endgroup$ Dec 24, 2020 at 12:35
  • 4
    $\begingroup$ I think generally it's a prudent recommendation to avoid Wikipedia as a reference for precise scientific values. The CRC handbook is a gold standard for a reason. $\endgroup$
    – J...
    Dec 25, 2020 at 14:58

1 Answer 1


According to the 97th edition of the CRC Handbook of Chemistry and Physics, table 1 Bond Dissociation Energies in Diatomic Molecules [1, p. 9-76]:

$$D^\circ_{298}(\ce{H-O}) = \pu{(429.74\pm 0.03) kJ mol-1}.$$

The value has been taken from the article by Ruscic et al. [2]. Note that this value is strictly for the diatomic molecule $\ce{OH}$ in gas phase and is determined as the standard enthalpy change for the fission process

$$\ce{O-H → O + H}.$$


  1. Haynes, W. M.; Lide, D. R.; Bruno, T. J. CRC Handbook of Chemistry and Physics: A Ready-Reference Book of Chemical and Physical Data, 97th ed.; Taylor & Francis Group (CRC Press): Boca Raton, FL, 2016. ISBN 978-1-4987-5429-3.
  2. Ruscic, B.; Feller, D.; Peterson, K. A. Active Thermochemical Tables: Dissociation Energies of Several Homonuclear First-Row Diatomics and Related Thermochemical Values. Theor Chem Acc 2014, 133 (1), 1415. DOI: 10.1007/s00214-013-1415-z.

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