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Delocalization of Electrons

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Hello any ppl HLing in chem

I really need help with delocalization of electrons my textbook explains it very badly and I have a test on bonding tomorrow.

Please can someone explain this or point me towards somewhere I can find help

Thanks

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I remember that we took it for the metallic bonding, it is postive ions in a "sea" of delocalised mobile electrons which basically means that positive ions are presnt and all around them are delcalised electrons (free to move)

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Great answers but you're missing the biggest point. If you've ever done ressonance structures then it's easier to understand. Here's an example that is quite easy to understand and will get you to understand the concept of delocalized electrons:

Imagine you have nitrate, NO3. I don't know if you can visualize this molecule, look it up online if you cant. Mainly its just the nitrogen in the middle surrounded by three oxygens. Clearly you can already see that the molecule is somewhat symetric except for the fact that there is one electron missing (nitrogen has 5 and to make 3 double bonds you'll need 6 electrons).

What happens is that the nitrogen will make two double bonds and one single leaving one of the oxygens with a negative charge (again if you don't know what I'm talking about it's all in the wikipedia picture of the three resonance structures of nitrate). BUT we already said that this molecule is symetric, so how come only one oxygen is getting a single bond while theothers have double? Well here's where the delocalization of electron comes in. That extra negative charge flying around in fact moves from oxygen to oxygen, and it is so fast that all three oxyges have single/double bonds at the same time forming what are called hybrids. The delocalization of the electron essentially means that the electron is de - localized or taken out of its home and if something isnt local then it is foreign meaning that this electron doesnt have a home and will jump around at the speed of light from one oxygen to the other.

The single/double bond caused by a delocalized electron is obvoiusly not as weak asa single yet not as strong as a double. But most importantly it STABALIZES a molecule. In the HL test or any other chemistry test you'll ever take, the delocalization of an electron will come up in a question as the factor responsable for making a molecule more stable. If you think about it, what it does is give the molecule symetry. Other molecules that have charges but don't resonate are much more reactive and less stable since they become polar. Molecules like nitrate that resonate will simply be neutral since the electron movs so fast that its as if it were in all places at the same time (look up String Theory).

I don't know what else to explain thats pretty much it. Delocalization explains other things too like boiling point and other more advanced organic chemistry applications but they all fall back on the strenght of the bonds and intermolecular forces though all you need to know is that the more resonance structures the more stable it is.

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[quote name='ezex' post='30250' date='Dec 14 2008, 05:16 PM']Great answers but you're missing the biggest point. If you've ever done ressonance structures then it's easier to understand. Here's an example that is quite easy to understand and will get you to understand the concept of delocalized electrons:

...

I don't know what else to explain thats pretty much it. Delocalization explains other things too like boiling point and other more advanced organic chemistry applications but they all fall back on the strenght of the bonds and intermolecular forces though all you need to know is that the more resonance structures the more stable it is.[/quote]

Omfg thank you that helped so much!!!!!!!!!!!!!!! Edited by Bittersweet

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No problem, that's what we're here for :P And feel free to ask as many questions as you want since I'm done with all the IAs/EE/CAS/college essays/college finals/life so i'll have free time from now till...next year.

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