Bond energy explanations say the number given is often an average.

For instance, in methane, the $\ce{C-H}$ bond dissociation energy is the total energy required to remove all four hydrogens, divided by four. $(\pu{415.5 kJ/mol})$

But, removing the first hydrogen atom is harder than the second or third ($\pu{439 kJ/mol}$ for the first). Why?

  • $\begingroup$ Pardon me, I just read that removing the second hydrogen is harder than removing the first, not easier. But the third is easier than the first two, and the fourth easiest of all. But, I am still curious as to why.... $\endgroup$ – Kurt Hikes Jun 6 '19 at 14:24
  • $\begingroup$ What is your take? Let's hear that first. $\endgroup$ – Mathew Mahindaratne Jun 6 '19 at 15:36
  • $\begingroup$ I believe unpaired and/or 'nonbonding' valence electrons interfere somehow with the other bonds/electrons.... $\endgroup$ – Kurt Hikes Jun 6 '19 at 15:45
  • $\begingroup$ @KurtHikes Note that you can edit your question if you feel it needs to be corrected. For instance, you can convert your first comment into an edit. $\endgroup$ – andselisk Jun 6 '19 at 16:36

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