Polar Molecules

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Sarah Zhari 1D
Posts: 103
Joined: Sat Sep 14, 2019 12:16 am

Polar Molecules

Postby Sarah Zhari 1D » Sat Nov 09, 2019 6:24 pm

What exactly determines the polarity of a particular molecule? Is there a specific difference in electronegativity between two elements that is needed in order for a molecule to be polar?

claribel charway 1I
Posts: 55
Joined: Wed Sep 11, 2019 12:15 am

Re: Polar Molecules

Postby claribel charway 1I » Sat Nov 09, 2019 6:57 pm

If the electronegativity difference is greater than 2 then it is polar. It could be either ionic polar or covalent polar.

WYacob_2C
Posts: 102
Joined: Sat Jul 20, 2019 12:16 am

Re: Polar Molecules

Postby WYacob_2C » Sat Nov 09, 2019 9:32 pm

It depends on the difference in electronegativity. If the difference between the molecules' electronegativity values is larger than 2.0, the molecule is polar. Polarity is simply the unequal pull of electrons. If electronegativity is the ability to pull an electron, two molecules with very different electronegativity would have an unequal share of electrons, since one would be able to pull in electrons more than the other.

Ashley R 1A
Posts: 41
Joined: Sat Aug 24, 2019 12:16 am

Re: Polar Molecules

Postby Ashley R 1A » Mon Nov 11, 2019 12:24 am

Although molecules can have polar covalent bonds, there are a few exceptions where the dipole moments cancel each other out; thus, creating non-polar molecules that have polar bonds.

Ex: CO2 and CCl4

While both C=O and C-Cl bonds are polar, the dipole moments cancel each other out due to their linear and their tetrahedral structures respectively.

Liliana Aguas 3G
Posts: 59
Joined: Wed Sep 18, 2019 12:20 am

Re: Polar Molecules

Postby Liliana Aguas 3G » Wed Nov 13, 2019 6:52 pm

Ashley R 1A wrote:Although molecules can have polar covalent bonds, there are a few exceptions where the dipole moments cancel each other out; thus, creating non-polar molecules that have polar bonds.

Ex: CO2 and CCl4

While both C=O and C-Cl bonds are polar, the dipole moments cancel each other out due to their linear and their tetrahedral structures respectively.


So if we are not given electronegativity of each molecule to determine if it is polar or non-polar then we use the structure? I'm Just confused how do you know which structures will cancel out the dipole moments? Is it only the ones with the same bond angle distribution? Like a tetrahedral in the CCl(4), the bond angles are all 109.5 and the linear. If you could please explain why.


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