Determining Type of Bond from Shape

(Polar molecules, Non-polar molecules, etc.)

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Kyle Walsh 2J
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Joined: Wed Sep 30, 2020 9:48 pm

Determining Type of Bond from Shape

Postby Kyle Walsh 2J » Sun Nov 29, 2020 11:44 pm

Hi! I was just curious as to if the type of bond (i.e. pi or sigma), can be determined purely from the shape of the molecule, or if you need to draw out the Lewis structure every time. I might just be forgetting but I can't remember if this was discussed. Thanks!

Ryan Hoang 1D
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Joined: Wed Sep 30, 2020 9:49 pm

Re: Determining Type of Bond from Shape

Postby Ryan Hoang 1D » Sun Nov 29, 2020 11:45 pm

Remember that shape doesn't necessarily give you the amount of bonds. IE: A double bond would still be seen as one region of electrons, not two. Because of this, I'd advise to draw out the lewis structure every time.

Zach Richardson 2f
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Re: Determining Type of Bond from Shape

Postby Zach Richardson 2f » Sun Nov 29, 2020 11:51 pm

The lewis structure will show you the kind of bond because the shape will not tell you if a bond is single or double or triple.

Alan Huang 1E
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Re: Determining Type of Bond from Shape

Postby Alan Huang 1E » Sun Nov 29, 2020 11:55 pm

You probably should draw the Lewis Structure out every time since molecular shape doesn't tell you anything about which bonds they are.

Sarah Salam 1J
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Re: Determining Type of Bond from Shape

Postby Sarah Salam 1J » Sun Nov 29, 2020 11:56 pm

No, you will need to draw the Lewis structure to determine if the bonds are single, double or triple.

Griffin G
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Re: Determining Type of Bond from Shape

Postby Griffin G » Sun Nov 29, 2020 11:57 pm

Unfortunately, shape alone wouldn't give you enough information. You would also need to know the lewis structure.

Ven Chavez 2K
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Re: Determining Type of Bond from Shape

Postby Ven Chavez 2K » Mon Nov 30, 2020 12:10 pm

It is important to draw out the lewis structure because the shape will not tell you the type of bond. A double bond, triple bond, and single bond count as one region of electron density.

Margaret Wang 2D
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Re: Determining Type of Bond from Shape

Postby Margaret Wang 2D » Mon Nov 30, 2020 12:12 pm

It doesn't because single, double, and triple bonds in one location are all considered one region of electron density so it will result in the same shape!

Annika Tamaki 1E
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Re: Determining Type of Bond from Shape

Postby Annika Tamaki 1E » Mon Nov 30, 2020 12:21 pm

You cannot tell the type of bond just based on the shape, since double and triple bonds are still regarded as one region of electron density. You must draw the lewis dot structure to know. Hope this helps!

Katie Nye 2F
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Joined: Wed Sep 30, 2020 9:55 pm

Re: Determining Type of Bond from Shape

Postby Katie Nye 2F » Mon Nov 30, 2020 12:23 pm

The type of bond is based on how many bonds exist in one region of density. Shape can only help you determine how many sigma bonds there are because one exists in each bond but you have to create the Lewis structure to determine if any bonds are double or triple because that is where pi bonds come in.

EnricoArambulo3H
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Re: Determining Type of Bond from Shape

Postby EnricoArambulo3H » Mon Nov 30, 2020 12:24 pm

It would be best to draw out the shape since the presence of multiple bonds does not indicate the geometry. For example, both the carbonate ion and BF3 both are trigonal planar, even though carbonate has a delocalized double bond. I hope this helped!

105618850
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Joined: Wed Sep 30, 2020 9:38 pm

Re: Determining Type of Bond from Shape

Postby 105618850 » Wed Dec 02, 2020 2:06 am

Only a lewis dot structure would allow you to identify the types of bonds (single, double, triple) and therefore, determine the number of pi bonds. However, molecular shape does not include the information needed to determine the number of pi bonds in a molecule.

Inderpal Singh 2L
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Re: Determining Type of Bond from Shape

Postby Inderpal Singh 2L » Wed Dec 02, 2020 1:23 pm

Make sure you always draw out the Lewis Structure!


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