Bond lengths

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Lusin_Yengibaryan_3B
Posts: 103
Joined: Wed Sep 30, 2020 9:33 pm

Bond lengths

Postby Lusin_Yengibaryan_3B » Fri Nov 06, 2020 3:00 pm

When drawing lewis structures, do we have to draw the double bond shorter than the single bonds? If so, why is this the case?

Claire_Latendresse_1E
Posts: 130
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Re: Bond lengths

Postby Claire_Latendresse_1E » Fri Nov 06, 2020 3:05 pm

Hi!

You don't have to draw the double bonds shorter because Lewis structures aren't that particular. Knowing that double bonds and triple bonds are shorter is the important part :)

Ashley Kim 3H
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Re: Bond lengths

Postby Ashley Kim 3H » Fri Nov 06, 2020 3:07 pm

Hi, I don't think we actually have to draw the double bonds shorter than single bonds for accuracy. I think we should just be able to know that single bonds are longer than double bonds, which are longer than triple bonds.

Kristina Krivenko 3I
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Re: Bond lengths

Postby Kristina Krivenko 3I » Fri Nov 06, 2020 6:30 pm

We don't have to draw double / triple bonds shorter than single bonds when drawing Lewis structures. Lewis structures are just a way to represent what molecule structure looks like, so they don't have to drawn to scale. Just know that the bond length decreases as the number of bonds increases :)

Colin Squire 3B
Posts: 90
Joined: Wed Sep 30, 2020 9:35 pm

Re: Bond lengths

Postby Colin Squire 3B » Fri Nov 06, 2020 6:36 pm

Hello! I think its implied that we already know that double bonds are shorter than single bonds, so I don't think we will need to draw them out shorter. The Lewis structure is a representation of what it would simply look like!

Navdha Sharma 3J
Posts: 96
Joined: Wed Sep 30, 2020 9:46 pm

Re: Bond lengths

Postby Navdha Sharma 3J » Fri Nov 06, 2020 8:24 pm

I don't think that we actually have to draw the double bonds shorter. Knowing that double bonds are shorter is enough!

Crystal Pan 2G
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Re: Bond lengths

Postby Crystal Pan 2G » Fri Nov 06, 2020 10:14 pm

We don't have to draw them to be longer vs shorter, but we should know double bonds are shorter and single bonds are longer.

VincentLe_3A
Posts: 91
Joined: Wed Sep 30, 2020 10:01 pm

Re: Bond lengths

Postby VincentLe_3A » Fri Nov 06, 2020 10:39 pm

I believe it is just conceptually important to understand that double bonds are shorter than single bonds, but we do not have to visually show it on the Lewis structures because the main focus of the Lewis structures is the valence electrons and the relationship of the valence electrons between different elements within a molecule.

DominicMalilay 1F
Posts: 107
Joined: Wed Sep 30, 2020 9:36 pm

Re: Bond lengths

Postby DominicMalilay 1F » Fri Nov 06, 2020 10:40 pm

No, you don't need to draw the bonds shorter or longer!

Shruti Kulkarni 2I
Posts: 100
Joined: Thu Oct 08, 2020 12:16 am

Re: Bond lengths

Postby Shruti Kulkarni 2I » Sat Nov 07, 2020 12:03 am

Hi! I'm pretty sure that the length of the bonds in your Lewis Structures don't matter as long as you conceptually understand that double and triple bonds are shorter and the reasoning behind this.

Emma Strassner 1J
Posts: 92
Joined: Wed Sep 30, 2020 9:50 pm

Re: Bond lengths

Postby Emma Strassner 1J » Sat Nov 07, 2020 3:35 pm

Hi, the drawings themselves are not very particular about the lengths of the bonds. You can draw them the same and it'll be fine, just remember that they are shorter in reality even though it is not needed in the drawing.

AndrewNguyen_2H
Posts: 90
Joined: Wed Sep 30, 2020 9:59 pm

Re: Bond lengths

Postby AndrewNguyen_2H » Sat Nov 07, 2020 3:36 pm

No, Lewis structures are a simplified model. There's no need to show a shorter line.

George_Yin_3I
Posts: 50
Joined: Wed Sep 30, 2020 9:42 pm

Re: Bond lengths

Postby George_Yin_3I » Sun Nov 08, 2020 4:10 am

No, you do not need to do that. Lewis structure is basically a demonstration of bond types, so there is no need to represent the bond lengths.

George_Yin_3I
Posts: 50
Joined: Wed Sep 30, 2020 9:42 pm

Re: Bond lengths

Postby George_Yin_3I » Sun Nov 08, 2020 4:10 am

No, you do not need to do that. Lewis structure is basically a demonstration of bond types, so there is no need to represent the bond lengths.

Emma Chang 1G
Posts: 52
Joined: Wed Sep 30, 2020 10:02 pm

Re: Bond lengths

Postby Emma Chang 1G » Sun Nov 08, 2020 11:33 am

I don't think we have to draw double bonds shorter than single bonds since Lewis structures are simplified models. I think it's fine to draw them with the same lengths as long as we understand conceptually that double bonds are shorter than single bonds!

Mackenzie Stockton 2H
Posts: 97
Joined: Wed Sep 30, 2020 10:11 pm

Re: Bond lengths

Postby Mackenzie Stockton 2H » Sun Nov 08, 2020 11:44 am

I don't think that you have to do that, at least for this class! However, I know that a double bond is stronger than a single bond, so that may be why you draw the double bonds as shorter in some cases.

Will Skinner
Posts: 84
Joined: Wed Sep 30, 2020 9:28 pm

Re: Bond lengths

Postby Will Skinner » Sun Nov 08, 2020 11:48 am

No. I do not think Lewis structures are meant to be that precise.

Claudia_Danysh_2B
Posts: 89
Joined: Wed Sep 30, 2020 9:58 pm

Re: Bond lengths

Postby Claudia_Danysh_2B » Sun Nov 08, 2020 10:07 pm

Hi! No you don't because the way you can denote a double bond is by drawing two shared bond lines instead of one!

MMorcus2E
Posts: 96
Joined: Wed Sep 30, 2020 9:47 pm

Re: Bond lengths

Postby MMorcus2E » Sun Nov 08, 2020 10:21 pm

No because the point of Lewis Structure is to show where electrons are and if they are shared with other atoms. In the Lewis structure, double and triple bonds are indicated by having two or three pairs of electrons between the 2 different atoms. So showing bond length is not necessary.

Zach Richardson 2f
Posts: 68
Joined: Wed Sep 30, 2020 9:32 pm

Re: Bond lengths

Postby Zach Richardson 2f » Sun Nov 08, 2020 11:23 pm

No it is not necessary because Lewis structures are simplified models and do not actually represent the molecule in physical space.

Lily Mohtashami
Posts: 142
Joined: Wed Sep 30, 2020 9:34 pm

Re: Bond lengths

Postby Lily Mohtashami » Mon Nov 09, 2020 2:02 pm

No you don't! However knowing the bond length will be important when finding the dipole moment so it is definitely good to know!


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