Bond Lengths [ENDORSED]

[alyssawhite1L]

There was a question that asked us to compare the bond lengths of different molecules. In part a it had us compare a single to double to triple bond. However, in part b, it had us compare a molecule that had 1 single bond and one double bond, and a molecule that had 2 single bonds and one double bond. The answers said they have nearly the same bond length and i was wondering why this is? Wouldnt the one with 2 single bonds have longer bond length?

[Cooper1C]

This could be because of resonance. The molecule is an average of the resonance structures, so the bond length is an average as well.

[donnanguyen1d]

I think that the sum of two single bonds is stronger than a double bond; therefore, it is probably shorter or about the same length.

[Evelyn L 1H]

single bonds are the weakest and longest, double bonds are stronger and shorter than single bonds, and triple bonds are the strongest and the shortest