Sulfite Ion example in class

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Amina Durrani 3G
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Joined: Sat Jul 20, 2019 12:16 am

Sulfite Ion example in class

Postby Amina Durrani 3G » Sat Nov 16, 2019 12:56 pm

In my notes I wrote that the bond angles of O-S-O are 106 degrees not 109.5 degrees, but why is this?

Angus Wu_4G
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Joined: Fri Aug 02, 2019 12:15 am

Re: Sulfite Ion example in class

Postby Angus Wu_4G » Sat Nov 16, 2019 1:02 pm

This is because the sulfur atom in the sulfite ion has a lone pair, and the lone pair present causes electron-electron repulsion, and therefore forces all the other bonds to be just slightly closer to each other. This is why the bond angle is 106, slightly less than the standard value of 109.5, which is the bond angle one would find in a tetrahedral with no lone pairs.

Robert Tran 1B
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Joined: Thu Jul 11, 2019 12:15 am

Re: Sulfite Ion example in class

Postby Robert Tran 1B » Sat Nov 16, 2019 2:33 pm

The lone pairs in the sulfite ion cause the bond angles to be slightly smaller because the electron-electron repulsion pushes the bonds closer together.

Rodrigo2J
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Joined: Sat Jul 20, 2019 12:16 am

Re: Sulfite Ion example in class

Postby Rodrigo2J » Sat Nov 16, 2019 2:36 pm

Remember that in a sulfite ion there is a lone pair of electrons attached to the sulfur atom. Because lone pairs are more repulsive than atoms, they slightly change the bond angles between the atoms to slightly less than 109.5 degrees. We don't have know the exact bond angles, we just say that they are slightly less or slightly more than whatever the bond angle in question is. At least I think so.

AlyssaYeh_1B
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Joined: Sat Aug 17, 2019 12:16 am

Re: Sulfite Ion example in class

Postby AlyssaYeh_1B » Sat Nov 16, 2019 3:22 pm

Since lone pair electrons have stronger repulsion force, bonded atoms will be pushed further from it and gather closer to each other. This is more stable, since atom-atom repulsion is weaker than lone pair-atom repulsion. We don't need to memorize that the particular bond angle is 106 degrees. We only need to be able to understand that this structure has a lone pair, and thus the bond angles must be smaller than the expected tetrahedral bond angle (109.5)

Sadhana_Dicussion_4A
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Joined: Sat Sep 07, 2019 12:19 am

Re: Sulfite Ion example in class

Postby Sadhana_Dicussion_4A » Sat Nov 16, 2019 3:43 pm

Since the sulfite ion has a lone pair, this causes a little more repulsion, causing the bond angles to be slightly less than 109 degrees.

Megan Ngai- 3B
Posts: 50
Joined: Fri Aug 09, 2019 12:17 am

Re: Sulfite Ion example in class

Postby Megan Ngai- 3B » Sat Nov 16, 2019 3:48 pm

The lone pair creates an electron electron repulsion. Therefore, it'll push the bonded atoms away from it but push them closer to each other.


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