Bond Order and # of Electrons for stability

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HoganFenster2E
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Joined: Fri Sep 25, 2015 3:00 am

Bond Order and # of Electrons for stability

Postby HoganFenster2E » Sat Oct 31, 2015 12:04 pm

I know that the higher the bond order the more stable the molecule, but how does number of electrons (perhaps bonded or unbounded) play into how stable a molecule is? The question I am referring to gives both the bond order and number of electrons for a compound and asks for increasing stability, but the answer is not just arranging them from lowest bond order to highest bond order. So how do the electrons play into stability?

amyjunus1A
Posts: 26
Joined: Fri Sep 25, 2015 3:00 am

Re: Bond Order and # of Electrons for stability

Postby amyjunus1A » Sat Oct 31, 2015 12:09 pm

It may help to post what question this is, because I am not too sure.
However, I can say that perhaps this question has to do with lone pairs on the molecule, which would lead to less stability.

Aleck Sun 1J
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Joined: Fri Sep 25, 2015 3:00 am

Re: Bond Order and # of Electrons for stability

Postby Aleck Sun 1J » Sat Oct 31, 2015 5:16 pm

If you are referring to the workbook Quiz #2 preparation Fall 2013 question 5, then the answer of increasing stability is valid. The higher the bond order, the more stable it is. In question 5, it gives both the electrons and the bond order, but I only looked at the bond order to determine the stability. And it was the right answer according to the solutions. I'm still not sure how electrons play into the role of stability, but it could be extraneous information just to throw people off.

Ulysis Baal 4J
Posts: 19
Joined: Fri Sep 25, 2015 3:00 am

Re: Bond Order and # of Electrons for stability

Postby Ulysis Baal 4J » Sun Nov 01, 2015 3:20 am

I agree with Alex Sun that all you need to know for question 5 is that when bond order is higher, stability is greater as well. However, in terms of electrons, I believe that stability is greater when there are more electrons that fill up the bonding orbitals (sigma and pi). Inversely, stability decreases when electrons start to fill up the anti bonding orbitals (sigma-star and pi-star). My deduction stems from Prof. Lavelle's example on Friday, when he worked through the MO diagram for F2, in which the electrons filled the molecular orbitals up to "pi-star 2py" (anti bonding). He eventually said that F2+ (the same diagram as F2 but missing one electron) was actually more stable, because there was one less electron in the anti-bonding electron (even though the molecule transitioned from no unpaired electrons to one unpaired electron).


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