Seesaw

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

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Michael Du 1E
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Joined: Sun Sep 22, 2019 12:16 am

Seesaw

Postby Michael Du 1E » Sun Nov 17, 2019 12:16 pm

According to the solution manual of E15, a seesaw would have an approximate angle of 90 and 120 degrees. Wouldn't the angles be less than 90 and 120 due to the lone pair causing a smaller angle than the typical angles of an electron arrangement of a trigonal bipyramidal?

Verity Lai 2K
Posts: 80
Joined: Sat Aug 24, 2019 12:18 am

Re: Seesaw

Postby Verity Lai 2K » Sun Nov 17, 2019 12:33 pm

I think your right, the lone pair-bonding pair electron repulsion is stronger than the bonding pair-bonding pair electron repulsion so the bond angles are slightly smaller than if it was all atoms.

MaggieHan1L
Posts: 81
Joined: Thu Jul 11, 2019 12:17 am

Re: Seesaw

Postby MaggieHan1L » Sun Nov 17, 2019 2:15 pm

I don't know if the angle has a difference that is significant. 90 and 120 should be fine.

Siya Shah 1J
Posts: 50
Joined: Sat Aug 17, 2019 12:15 am

Re: Seesaw

Postby Siya Shah 1J » Sun Nov 17, 2019 2:39 pm

You're definitely right; the lone pair should cause enough repulsion to distort the angles at least slightly in comparison to the bond angles of a trigonal bipyramidal molecule. I assume that's where the "approximately" 90º and 120º comes in?

ranqiao1e
Posts: 51
Joined: Sat Sep 14, 2019 12:15 am

Re: Seesaw

Postby ranqiao1e » Fri Nov 22, 2019 10:24 pm

Yes it is less because lone pair would require some kind of experiment to determine its actual value

Astrid Lunde 1I
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Joined: Sat Sep 07, 2019 12:16 am

Re: Seesaw

Postby Astrid Lunde 1I » Sat Nov 23, 2019 6:28 pm

Yes, it would be less because the lone pairs push on the other bonds.

Maddie
Posts: 50
Joined: Wed Sep 11, 2019 12:17 am

Re: Seesaw

Postby Maddie » Sat Nov 23, 2019 7:48 pm

Yes almost every time there is a lone pair on the model the angle will slightly diminish.

Mallika Chimpiri 3K
Posts: 58
Joined: Thu Jul 25, 2019 12:17 am

Re: Seesaw

Postby Mallika Chimpiri 3K » Sat Nov 23, 2019 8:13 pm

Yes, it should be less than 90 and 120.

Jasmine Vallarta 2L
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Joined: Sat Aug 17, 2019 12:18 am

Re: Seesaw

Postby Jasmine Vallarta 2L » Sat Nov 23, 2019 8:23 pm

yes

Bradley Whitworth 4B
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Joined: Sat Jul 20, 2019 12:17 am

Re: Seesaw

Postby Bradley Whitworth 4B » Sun Nov 24, 2019 1:09 am

Technically yes so I'd be precise on a test but it is a small difference so the manual might just be counting it as negligible.

Rishika Yadav 3D
Posts: 53
Joined: Wed Sep 11, 2019 12:17 am

Re: Seesaw

Postby Rishika Yadav 3D » Sun Nov 24, 2019 11:57 am

My TA told me that if there are lone pairs, always write less than the respective number of degrees. Thus I think you are right, see saw should be less than 90 an 120 degrees.

Matt F
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Joined: Sat Aug 17, 2019 12:17 am

Re: Seesaw

Postby Matt F » Sun Nov 24, 2019 12:33 pm

I have in my notes that they are equal to 90 and 120, but I think using the lone pair as reasoning you wouldn't be marked wrong for writing less than 90 and less than 120

Celine 1F
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Joined: Fri Aug 02, 2019 12:16 am

Re: Seesaw

Postby Celine 1F » Sun Nov 24, 2019 12:42 pm

Yes it should be less than 9- or 120 because the lone pairs should create a repulsion.

Mariah
Posts: 78
Joined: Fri Aug 02, 2019 12:16 am

Re: Seesaw

Postby Mariah » Sun Nov 24, 2019 1:22 pm

Michael Du 3J wrote:According to the solution manual of E15, a seesaw would have an approximate angle of 90 and 120 degrees. Wouldn't the angles be less than 90 and 120 due to the lone pair causing a smaller angle than the typical angles of an electron arrangement of a trigonal bipyramidal?


It is less than 120 or 90 because of the lone pair repulsion.

zfinn
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Joined: Fri Aug 30, 2019 12:16 am

Re: Seesaw

Postby zfinn » Sun Nov 24, 2019 1:56 pm

The bond angles would be less because lone-bonding pars have more repulsion

Lauren Lewis3L
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Joined: Wed Feb 20, 2019 12:16 am

Re: Seesaw

Postby Lauren Lewis3L » Sun Nov 24, 2019 5:00 pm

Yes, the see-saw is less then 90 and 120 degrees because there are lone pairs. Lone pairs create repulsion which brings the atoms together lowering their original angle.

Reagan Smith 1H
Posts: 50
Joined: Sat Jul 20, 2019 12:16 am

Re: Seesaw

Postby Reagan Smith 1H » Sun Nov 24, 2019 5:03 pm

Yes it is "about" 90 and 120, so if you want to be more precise you can say "slightly less than 90" or "slightly less than 120".

Sanjana Borle 2K
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Joined: Fri Aug 09, 2019 12:15 am

Re: Seesaw

Postby Sanjana Borle 2K » Sun Nov 24, 2019 5:05 pm

Since there is a lone pair that replaces the atom in a trigonal bipyramidal, it "pushes" on the other atoms and causes their bond angles to decrease.

J Medina 2I
Posts: 78
Joined: Wed Sep 25, 2019 12:17 am

Re: Seesaw

Postby J Medina 2I » Sun Nov 24, 2019 5:07 pm

If a lone pair is present in a molecule, then it will affect the bond angles of the surrounding atoms since the repulsion force lone pairs is greater than bonded atoms.

faithkim1L
Posts: 85
Joined: Fri Aug 09, 2019 12:17 am

Re: Seesaw

Postby faithkim1L » Sun Nov 24, 2019 5:16 pm

Because there is a lone pair, the angles should be slightly less than 90 and 120.

Tahlia Mullins
Posts: 85
Joined: Thu Jul 25, 2019 12:15 am

Re: Seesaw

Postby Tahlia Mullins » Sun Nov 24, 2019 5:59 pm

A lone pair should always change the angle at least slightly, so the actual angles would be less than 90 and 120.

Megan Jung 3A
Posts: 50
Joined: Thu Jul 11, 2019 12:17 am

Re: Seesaw

Postby Megan Jung 3A » Sun Nov 24, 2019 6:04 pm

Yes, due to the lone pair repulsion the angles would be slightly less than 90 and 120.

Rosa Munoz 2E
Posts: 84
Joined: Wed Sep 18, 2019 12:21 am

Re: Seesaw

Postby Rosa Munoz 2E » Sun Nov 24, 2019 8:53 pm

yes

Juana Abana 1G
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Joined: Wed Sep 18, 2019 12:15 am

Re: Seesaw

Postby Juana Abana 1G » Sun Nov 24, 2019 9:16 pm

Yes, it should be less than 90 or 120 because of the lone pair repulsion.


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