Homework question Sapling

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Claire_Kim_2F
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Homework question Sapling

Postby Claire_Kim_2F » Mon Nov 23, 2020 5:48 pm

For the x-y-x question on the homework with two lone pairs on each side of the y why would that be a bent I thought the two lone pairs would cancel each other in force and it would make it a linear shape?

Hannah Lechtzin 1K
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Re: Homework question Sapling

Postby Hannah Lechtzin 1K » Mon Nov 23, 2020 6:19 pm

The two lone pairs will not cancel out. Instead they repel the two x atoms which forces them to have a smaller bond angle than a linear molecule would have. This bond angle creates the bent shape. For example water (H2O) is bent and has two lone pairs. Just remember that any chemical with the formula
and two lone pairs will be bent/angular.

Shrey Pawar 2A
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Re: Homework question Sapling

Postby Shrey Pawar 2A » Mon Nov 23, 2020 7:30 pm

I do not believe that lone pairs can cancel out, only polarities or dipoles can cancel out to make a molecule polar or nonpolar. Hopefully this helps!

Joseph_Armani_3K
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Re: Homework question Sapling

Postby Joseph_Armani_3K » Wed Nov 25, 2020 3:29 pm

If it were linear and the two lone pairs cancel its forces out, then the angle between the lone pair and the bond would be 90 degrees, and electron repulsion wouldn't allow that. When there are four regions of electron density, the electron geometry is tetrahedral and the bond angles are 109.5 degrees, so the two terminal atoms will be in a bent shape. I'm guessing you were confused because the lewis structure shows the two lone pairs on opposite ends.

Arezo Ahmadi 3J
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Re: Homework question Sapling

Postby Arezo Ahmadi 3J » Wed Nov 25, 2020 5:24 pm

In this example, there are four electron densities with two being lone pairs, and this means that there is going to be repulsion from these lone pairs, making the bond angles less than 109.5 degrees. As a result of this shape, the name of the shape is bent instead of linear. Hope this helps!

Mahika More 1H
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Re: Homework question Sapling

Postby Mahika More 1H » Thu Nov 26, 2020 1:38 pm

Lone pairs do not cancel out. Rather they play a larger role in repelling atoms around/near it.

AHUNT_1A
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Re: Homework question Sapling

Postby AHUNT_1A » Fri Nov 27, 2020 9:39 am

Joseph_Armani_3K wrote:If it were linear and the two lone pairs cancel its forces out, then the angle between the lone pair and the bond would be 90 degrees, and electron repulsion wouldn't allow that. When there are four regions of electron density, the electron geometry is tetrahedral and the bond angles are 109.5 degrees, so the two terminal atoms will be in a bent shape. I'm guessing you were confused because the lewis structure shows the two lone pairs on opposite ends.



Extremely helpful explanation.


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