Drawing Lewis Structures on Midterm

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Connie Liang 3L
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Drawing Lewis Structures on Midterm

Postby Connie Liang 3L » Fri Nov 13, 2020 6:04 pm

If asked to draw a Lewis Structure on the midterm, will we be expected to draw the structure with the lowest total formal charge?

Emma_Barrall_3J
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Re: Drawing Lewis Structures on Midterm

Postby Emma_Barrall_3J » Fri Nov 13, 2020 6:08 pm

The structure with the lowest formal charge is the most correct structure so I would say yes.

Ryan Laureano 3I
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Re: Drawing Lewis Structures on Midterm

Postby Ryan Laureano 3I » Fri Nov 13, 2020 6:09 pm

Total formal charge is the same for a molecule regardless of electron distribution. I'm pretty sure you are talking about individual atoms, in which case you would draw for the lowest formal charge unless told otherwise.

Julianna Shimabukuro 1D
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Re: Drawing Lewis Structures on Midterm

Postby Julianna Shimabukuro 1D » Fri Nov 13, 2020 6:31 pm

Yes. I would advise drawing the structure with the least formal charges since this is considered the most plausible unless otherwise told. However, you should be able to identify the resonance structures if they have different placements of the double bonds and different formal charges on the structures in the midterm.

Kayla Booker 1F
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Re: Drawing Lewis Structures on Midterm

Postby Kayla Booker 1F » Fri Nov 13, 2020 7:30 pm

I would think so, the lowest formal charge would be the most accurate, but maybe recognize multiple structures just in case.

SavannahScriven_1F
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Re: Drawing Lewis Structures on Midterm

Postby SavannahScriven_1F » Fri Nov 13, 2020 8:38 pm

I also have a question about drawing lewis structures on the midterm. I noticed that sometimes the textbook writes the molecular formula in the order it wants us to draw the lewis structure, even if this order doesn't minimize formal charge. Like ClNO2 would be drawn with Cl attached to N, and then 2 Os attached to N. But if the molecule were drawn O=N-O-Cl, all elements would have a formal charge of 0. How would we know which one is preferred on the midterm? Or is the example I gave an exception to the formal charge rule because NO2 is supposed to stay together?

alebenavides
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Re: Drawing Lewis Structures on Midterm

Postby alebenavides » Sat Nov 14, 2020 2:18 pm

if we're drawing lewis structures on the midterm is it going to be how it is on sapling?

Sana Nagori 2H
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Re: Drawing Lewis Structures on Midterm

Postby Sana Nagori 2H » Sat Nov 14, 2020 3:23 pm

alebenavides wrote:if we're drawing lewis structures on the midterm is it going to be how it is on sapling?


I think the exam is multiple choice like the last one so we probably will only have to choose what is the correct answer.

Sana Nagori 2H
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Re: Drawing Lewis Structures on Midterm

Postby Sana Nagori 2H » Sat Nov 14, 2020 3:31 pm

SavannahScriven_2E wrote:I also have a question about drawing lewis structures on the midterm. I noticed that sometimes the textbook writes the molecular formula in the order it wants us to draw the lewis structure, even if this order doesn't minimize formal charge. Like ClNO2 would be drawn with Cl attached to N, and then 2 Os attached to N. But if the molecule were drawn O=N-O-Cl, all elements would have a formal charge of 0. How would we know which one is preferred on the midterm? Or is the example I gave an exception to the formal charge rule because NO2 is supposed to stay together?


I don't have a definite answer for you but since N is the least electronegative it would be the central atom and therefore it makes sense to put the Cl and O's around it. From the examples I've seen, the only time structures are drawn out linearly is if they give the molecular formula as ONOCl where it would be drawn in the order of the atoms given like O=N-O-Cl. I think the O2 in the problem is a good hint of the structure.

Nina Tartibi 1F
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Re: Drawing Lewis Structures on Midterm

Postby Nina Tartibi 1F » Sat Nov 14, 2020 4:23 pm

SavannahScriven_2E wrote:I also have a question about drawing lewis structures on the midterm. I noticed that sometimes the textbook writes the molecular formula in the order it wants us to draw the lewis structure, even if this order doesn't minimize formal charge. Like ClNO2 would be drawn with Cl attached to N, and then 2 Os attached to N. But if the molecule were drawn O=N-O-Cl, all elements would have a formal charge of 0. How would we know which one is preferred on the midterm? Or is the example I gave an exception to the formal charge rule because NO2 is supposed to stay together?


the central atom is generally the one with the lowest electronegativity so there can be a formal charge of 0 when making the Lewis structure, however in a workshop one of the problems had Carbon and Nitrogen and another element I'm forgetting and nitrogen was the central atom even though it's more electronegative? So I think write it based on the way it's given to you but I also am not 100% sure so if someone can confirm let me know!

Rajshree 1F
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Re: Drawing Lewis Structures on Midterm

Postby Rajshree 1F » Sat Nov 14, 2020 5:36 pm

Since the midterm is multiple choice I would suspect we would need to choose between some Lewis structures given to us. However, the structure with the least amount of atoms with a non-zero formal charge is usually the most accurate Lewis structure.

ellenulitsky Dis 1I
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Re: Drawing Lewis Structures on Midterm

Postby ellenulitsky Dis 1I » Sat Nov 14, 2020 5:39 pm

Yes, since when drawing the lewis structures, the most accurate ones are the ones that are the most stable. The closes to zero the lewis structure are the more stable it is! Hope this helps!

Emma Chang 1G
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Re: Drawing Lewis Structures on Midterm

Postby Emma Chang 1G » Sun Nov 15, 2020 12:37 am

Since the midterm is multiple choice, I'm assuming that we won't have to draw out Lewis structures like we did for the Sapling hw. My guess is that we'll have to identify the one Lewis structure out of a few structures that has the lowest total formal charge, since this one would generally be the most preferable. Hope this helps!

Brandon Le 3C
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Re: Drawing Lewis Structures on Midterm

Postby Brandon Le 3C » Sun Nov 15, 2020 12:44 am

We probably won't have to draw anything since the midterm is multiple-choice, but I would expect to see a question about which lewis structure is most plausible based on formal charge or oxidation number, just based on the homework.

vbarian27
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Re: Drawing Lewis Structures on Midterm

Postby vbarian27 » Sun Nov 15, 2020 12:53 am

I think the instructions will be clear of what they want, but in general when dealing with a structure with resonance you ideally want the molecule with a total charge closest to zero

MMorcus2E
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Re: Drawing Lewis Structures on Midterm

Postby MMorcus2E » Sun Nov 15, 2020 1:02 am

I also think that they would indicate what they want. I remember this one problem that I came across that put the elements in the chemical formula in the order that they want us to write the structure. If that is not the case, try to draw the most stable one, which is the one with the lowest formal charge.

Annette Fishman
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Re: Drawing Lewis Structures on Midterm

Postby Annette Fishman » Sun Nov 15, 2020 9:33 am

Instructions should be clear, but if not, least formal charge is the way to go. It is the most accurate, but I'd make sure to recognize multiple structures in case.

David He
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Re: Drawing Lewis Structures on Midterm

Postby David He » Sun Nov 15, 2020 10:56 am

I suppose the exam will be multiple choice only, so you will not actually draw the structure.

Aliya Roserie 3I
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Re: Drawing Lewis Structures on Midterm

Postby Aliya Roserie 3I » Sun Nov 15, 2020 11:03 am

The midterm is multiple choice, so the instructions should hopefully be clear if a drawing of the structure is needed. Most likely you would have to draw it, but the multiple choice would give you different structures to choose from. However, I advice you to draw the structure with the lowest formal charge since it is the most accurate Lewis structure.

Sophia Spungin 2E
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Re: Drawing Lewis Structures on Midterm

Postby Sophia Spungin 2E » Sun Nov 15, 2020 12:12 pm

Since it is multiple choice, I would expect that we would have to choose the diagram with formal charge minimized.

Danielle Goldwirth 3F
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Re: Drawing Lewis Structures on Midterm

Postby Danielle Goldwirth 3F » Sun Nov 15, 2020 3:47 pm

To select the lewis structure with the formal charges minimized, would we have to draw out all the resonances possible and calculate the formal charges before choosing an answer? Or we can just immediately draw out what works the first time and that will mean it must be the one with optimal formal charge.

DPatel_2L
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Re: Drawing Lewis Structures on Midterm

Postby DPatel_2L » Sun Nov 15, 2020 5:16 pm

The lowest formal change would be the mots accurate so I would think so.

RitaThomas_3G
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Re: Drawing Lewis Structures on Midterm

Postby RitaThomas_3G » Sun Nov 15, 2020 5:32 pm

I would assume so since that would be the most accurate. Also, since the midterm would be multiple choice and there are several correct structures, I would definitely try and go for the "best possible" answer.

Justin Lin 1B
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Re: Drawing Lewis Structures on Midterm

Postby Justin Lin 1B » Sun Nov 15, 2020 5:43 pm

The answers would most likely be multiple choice so we wouldn't have to draw them, but we should choose the structure with the lowest formal charge because those are the best represented structures.

Kyla Roche 2K
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Re: Drawing Lewis Structures on Midterm

Postby Kyla Roche 2K » Sun Nov 15, 2020 5:48 pm

The lewis structure with the lowest formal charge is preferred because it is most stable and less reactive. The lewis structure with the most amount of formal charges being 0 contributes the most to the overall structure.

Ashley Lopez 3J
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Re: Drawing Lewis Structures on Midterm

Postby Ashley Lopez 3J » Sun Nov 15, 2020 6:00 pm

Adding on, during a PLF session, I learned about Skeletal/Line structures, is there a possibility this may be on the midterm or are we just expected to draw the Lewis Structure with the lest F.C.?

Sukhkiran Kaur 3I
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Re: Drawing Lewis Structures on Midterm

Postby Sukhkiran Kaur 3I » Sun Nov 15, 2020 7:54 pm

I believe so yes.

Mariah Disc 2C
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Re: Drawing Lewis Structures on Midterm

Postby Mariah Disc 2C » Sun Nov 15, 2020 8:08 pm

I would assume that we are expected to draw the structure with the lowest formal change.

Mina Tadros 3L
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Re: Drawing Lewis Structures on Midterm

Postby Mina Tadros 3L » Sun Nov 15, 2020 8:10 pm

When drawing Lewis Structures, you should always draw the most stable and plausible structure, which would be the one with the least amount of formal charge.

Hannah Chang 3K
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Re: Drawing Lewis Structures on Midterm

Postby Hannah Chang 3K » Sun Nov 15, 2020 8:13 pm

I don't think we will be asked to draw lewis structures since it would be multiple choice questions, perhaps we will be asked to select from pictures that have the correct configuration.

Diana Aguilar 3H
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Re: Drawing Lewis Structures on Midterm

Postby Diana Aguilar 3H » Sun Nov 15, 2020 8:21 pm

I think we do have to draw the lewis structure with the lowest fromal charge since it is the most stable, but I don't think we will have to draw them on the midterm since it is multiple choice.

Jack Kettering 3D
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Re: Drawing Lewis Structures on Midterm

Postby Jack Kettering 3D » Sun Nov 15, 2020 8:22 pm

Yes we will be expected to select the most stable lewis structure representation based on formal charge.


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