6
$\begingroup$

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

What is the right value?

$\endgroup$
6
  • 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 '20 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. $\endgroup$ – Mathieu Krisztian Dec 24 '20 at 12:26
  • 4
    $\begingroup$ 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 '20 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 $\endgroup$ – Mathieu Krisztian Dec 24 '20 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 '20 at 14:58
10
$\begingroup$

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

$$\ce{O-H → O + H}.$$

References

  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.
$\endgroup$
0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.