Resonance in SO4

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clairedisc3b
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Resonance in SO4

Postby clairedisc3b » Fri Oct 27, 2017 2:26 pm

Hi, Today in class we learnt that the resonant structure of SO4 (2-) is when S has 2 double bonds and 2 single bonds, calculated using the formal charge. Why isnt having 4 double bonds more stable since the FC will be 0 for all of the O atoms?

Christian Fulinara 3H
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Re: Resonance in SO4

Postby Christian Fulinara 3H » Fri Oct 27, 2017 7:05 pm

Sulfur is not able to hold 16 valence electrons in its valence shell.

PranithaPrasad
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Re: Resonance in SO4

Postby PranithaPrasad » Fri Oct 27, 2017 8:47 pm

Also I think we want the central atom to have a formal charge be zero, or at least as close to 0 as it can get. If we made all the oxygen atoms have a formal charge of 0, we would have the total formal charge of -2, but the structure would be less stable since the formal charge of sulfur would become -2.

clairedisc3b
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Re: Resonance in SO4

Postby clairedisc3b » Fri Oct 27, 2017 9:42 pm

So the most important thing is to make sure the FC of the central atom is as close to 0 as possible?

Christina Cen 2J
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Re: Resonance in SO4

Postby Christina Cen 2J » Fri Oct 27, 2017 10:24 pm

I think the goal is the have the formal charge of all atoms to be as low as possible but having 4 double bonds for S is not possible.

Clarisse Wikstrom 1H
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Re: Resonance in SO4

Postby Clarisse Wikstrom 1H » Fri Oct 27, 2017 10:33 pm

The most ideal situation is...
1. Formal charge closest to zero
2. central atom w/o charge
3. charges (if any) distributed as evenly as possible among atoms (2- vs 1- and 1-)
Hope this helps!


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