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Drawing resonance

Posted: Sun Nov 11, 2018 2:10 pm
by 305117729
When we are drawing lewis structure of one molecule, should we always draw all resonance of this molecule?

Re: Drawing resonance

Posted: Sun Nov 11, 2018 2:14 pm
by Samantha Hoegl Roy 2C
if there is resonance, yes. You have to show that you know there are 3 different structures for the same molecule. if you only draw one, one could assume you believe one bond is shorter than the others

Re: Drawing resonance

Posted: Sun Nov 11, 2018 2:45 pm
by Connie Chen 3D
Yes, it is necessary to draw all the resonance structures in order to show that the overall bonds of the molecule are equal, not one greater than the other.

Re: Drawing resonance

Posted: Sun Nov 11, 2018 9:53 pm
by Karina Jiayu Xu 4E
Wait how do you know if there will be resonance structures on a molecule?

Re: Drawing resonance

Posted: Sun Nov 11, 2018 10:07 pm
by Sheridan Slaterbeck 1J
One of the TA's said we are not able to tell yet if a structure has resonance, we will learn that later. We will be told when to draw resonance structures as of now.

Re: Drawing resonance

Posted: Sun Nov 11, 2018 10:19 pm
by Alexandra Ortega 4D
I believe we should draw all resonance structures for molecules to show our understanding that lewis structures can have multiple bonds on different equivalent locations and that the actual molecule is a blend or average of all resonance structures.

Re: Drawing resonance

Posted: Sun Nov 11, 2018 10:57 pm
by Ruiting Jia 4D
If the problem itself does not indicate that we have to draw all the different resonance structures, I believe it is not needed.

Re: Drawing resonance

Posted: Sun Nov 11, 2018 11:19 pm
by Anjali 4A
In a exam/test situation, I think that it'll be safer to draw the resonance structure of the molecule.

Re: Drawing resonance

Posted: Mon Nov 12, 2018 4:25 pm
by Sophia Fox 4B
Yes draw all resonance structures and then double sided arrows between them indicating that there is resonance.

Re: Drawing resonance

Posted: Tue Nov 13, 2018 12:51 am
by Matthew Choi 2H
My TA said that sometimes the problem won't ask you to draw all of the possible resonance structures even if there are multiple resonance structures. This is because (1) they might not want to give away the fact that there are resonance structures in the specific problem or (2) they aren't asking for them. Either way, you should draw all the resonance structures and indicate them with double-sided arrows.

Re: Drawing resonance

Posted: Tue Nov 13, 2018 1:59 am
by Ethan Breaux 2F
If the bond can go anywhere then might as well draw the arrows I don't think it would ever hurt you.

Re: Drawing resonance

Posted: Tue Nov 13, 2018 9:49 am
by Erin Nash - 4G
You should always draw the resonance structures because the true structure of the molecule is a mixture of all of the resonance structures.

Re: Drawing resonance

Posted: Sun Nov 18, 2018 4:31 pm
by kimberlyrose1G
you should draw all of the resonance structures as the true structure will be an average of them all (so by drawing all of them, you show that you know that it can be any of the structures, but is an average in reality)

Re: Drawing resonance

Posted: Sun Nov 18, 2018 11:17 pm
by SophiaKohlhoff4B
It is important to draw the resonance for a molecule because it demonstrates that the actual bond lengths are the average of the bond lengths.

Re: Drawing resonance

Posted: Sun Nov 18, 2018 11:59 pm
by danicatran4
SophiaKohlhoff4B wrote:It is important to draw the resonance for a molecule because it demonstrates that the actual bond lengths are the average of the bond lengths.

Do we need to include something to show the bond lengths are an average and the same or is that implied when we draw the resonance structures?

Re: Drawing resonance

Posted: Mon Nov 19, 2018 12:25 am
by 505211599
I think that if a lewis structure has resonance, it would be safe to draw out all possible resonance structures.

Re: Drawing resonance

Posted: Sun Nov 25, 2018 5:31 pm
by SophiaKohlhoff4B
danicatran4 wrote:
SophiaKohlhoff4B wrote:It is important to draw the resonance for a molecule because it demonstrates that the actual bond lengths are the average of the bond lengths.

Do we need to include something to show the bond lengths are an average and the same or is that implied when we draw the resonance structures?


I don't think you need to include anything to show the bond lengths are an average, however it is important to understand in case a question is specifically asked about the actual bond lengths.

Re: Drawing resonance

Posted: Thu Nov 29, 2018 2:00 am
by Elizabeth Kim 4E
Even if it isn't required to draw all of the resonance structures, it's probably helpful in the long run to just draw them all out on tests and homework.