Determining Molecular Polarity using VSEPR

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

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Angel Gutierrez 2E
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Determining Molecular Polarity using VSEPR

Postby Angel Gutierrez 2E » Mon Nov 23, 2020 11:08 pm

Why would a linear shape describe a nonpolar molecule such as CO2?

Nane Onanyan 1G
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Re: Determining Molecular Polarity using VSEPR

Postby Nane Onanyan 1G » Mon Nov 23, 2020 11:11 pm

The two oxygens are pointing exactly 180 degrees away from eachother. Since the dipoles are on exact opposite sides of the central atom, they will cancel out.

John Pham 3L
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Re: Determining Molecular Polarity using VSEPR

Postby John Pham 3L » Mon Nov 23, 2020 11:14 pm

A linear shape describes a nonpolar molecule since the dipoles cancel each other out.

In the case of CO2, it has two polar bonds with the Carbon atom and each Oxygen atom.
But since they are placed opposite to each other, the dipoles cancel out and result in a nonpolar molecule

Andrew Jubintoro 3J
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Re: Determining Molecular Polarity using VSEPR

Postby Andrew Jubintoro 3J » Tue Nov 24, 2020 1:16 am

It really helps me to think of the dipole moments in bonds as vectors represented by arrows.
So when determining the polarity of CO2, the arrows point in completely opposite directions with the same magnitude. They cancel out. Therefore, the molecule is nonpolar.

Rose_Malki_3G
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Re: Determining Molecular Polarity using VSEPR

Postby Rose_Malki_3G » Tue Nov 24, 2020 1:40 am

This is because the dipoles cancel each other out, making the molecular non polar

Xinying Wang_3C
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Re: Determining Molecular Polarity using VSEPR

Postby Xinying Wang_3C » Tue Nov 24, 2020 2:33 am

Because as the whole molecule, the two ends are both oxygen atoms, which makes the molecule nonpolar.

AnnaNovoselov1G
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Re: Determining Molecular Polarity using VSEPR

Postby AnnaNovoselov1G » Tue Nov 24, 2020 8:57 am

CO2 has a total of 4+6+6=16 valence electrons. If we draw the Lewis structure, it would look like this:
::O=C=O::
We see that carbon has 2 regions of electron density, which corresponds to a linear shape. It would be nonpolar because the O and the O are directly opposite each other (form a 180 degree angle). Since the atoms are exactly the same, they have the same electronegativities and cancel each other out. Even though the C=O bond is polar, the molecule as a whole is nonpolar.
On the other hand, if we had H2O, there would be 2+6 valence electrons. It would look like
..
H-O-H
..

the oxygen is this case has 4 regions of electron density --> tetrahedral arrangement - 2 lone pairs = bent shape (which is polar)

derickngo3d
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Re: Determining Molecular Polarity using VSEPR

Postby derickngo3d » Tue Nov 24, 2020 8:05 pm

In CO2, the dipoles are directly opposite of each, so they cancel out, so the molecule is nonpolar.

Carly_Lipschitz_3H
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Re: Determining Molecular Polarity using VSEPR

Postby Carly_Lipschitz_3H » Tue Nov 24, 2020 10:35 pm

A linear shape would describe a nonpolar molecule such as CO2 because the dipoles are pointed in opposite directions, so they cancel each other out. This makes CO2 nonpolar.


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