Bond Lengths [ENDORSED]

[Sara Varadharajulu]

Why are multiple bonds shorter than a single bond between the same two elements?

[Christian Fulinara 3H]

"Multiple bonds are shorter than single bonds between the same two elements, because the additional bonding electrons attract the nuclei more strongly and pull the atoms closer together" (96). So basically, the more bonds there are, the shorter the bonds are.

[Nhan Nguyen 2F]

To elaborate on Christian's post,
Triple bonds are strongest, followed by doubles and single bonds. Bond length decreases as bond strength increases. Shorter bond lengths do not need to be long because attractions pull electrons closer.

[Guangyu Li 2J]

A single bond only has a pi bond. A double bond contains a pi bond and a sigma bond.

Whereas a pi bond is stronger and difficult to break, a sigma bond requires more energy to sustain the interaction between atoms. As a result, in order to form a sigma bond, two atoms have to be closer to each other. Therefore, a double bond is shorter than a single bond.

Hope this helps and have a nice weekend.

[Michelle Lee 2E]

In response to Guangyu Li's post, what would be the bond for a triple bond then? And is there any specific reason for the names, i.e. sigma and pi? We didn't learn this is lecture.

[Jasmine Botello 2F]

are we supposed to know about pi bonds for the midterm?? I do not remember going over them in class.

[Natalie LeRaybaud 1G]

No I don't think that you will have to know pi bonds for the midterm.

[Kai_Chiu 1F]

@Michelle Lee_3C, in a triple bond, there are two pi bonds and one sigma bond.

[Chem_Mod]

These are all correct. Remember, if something is not discussed in lecture, you are not responsible for knowing it! It's just extra information for the curious minds. :)