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Why is that carbonyl bonds are stronger than those of alkenes? It's a basic question but I've never really thought much about it. I've read several times that carbonyl bonds are shorter and you need to apply a higher amount of energy to break them. Why is that so?

Is it due to the electronegativity of oxygen, which pulls the bonding electrons near it, thus attracting the carbon as well?

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    $\begingroup$ Yes you are correct the electronegativity difference between C and O imparts partial ionic character to the bond. Consider that there is a partial negative charge on O and a partial positive charge on C and these charges attract each other. $\endgroup$ – Tan Yong Boon Oct 9 '18 at 23:03
  • $\begingroup$ I see. So the same can be said regarding the triple bond between carbon and nitrogen when compared to the alkyne bond? $\endgroup$ – Αντώνιος Κελεσίδης Oct 10 '18 at 7:54
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    $\begingroup$ Yes you are right. These charge separations may be slight in some cases but they do have significant consequences on bond strength. $\endgroup$ – Tan Yong Boon Oct 10 '18 at 12:01
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It's stronger because of a dipole moment. oxygen is more electronegative than carbon, so there is a stronger attraction between C and O than a C=C bond.

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  • $\begingroup$ A more polar bond is not necessarily stronger than a less polar one. $\endgroup$ – Martin - マーチン Nov 12 '18 at 17:48
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Basically there can be two reasons •electronegativity of oxygen is more than carbon which creates partial negative charge on oxygen and partial positive on carbon and they attract each other resulting in a shorter bond length • i consider the second reason more dominant- as oxygen is in same period as that of carbon and has greater atomic number too that is it is already having shorter size than carbon this means we will have C-C double bond longer than C-O double bond which will increse the bond strengh as bond length is shorter.....similarly the case of C-C triple bond and C-N triple bond

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  • $\begingroup$ Shorter bond length does not necessarily allow the conclusion that the bond is stronger. $\endgroup$ – Martin - マーチン Nov 12 '18 at 17:47

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