Nonpolar and polar

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Jessica Tejero 3L
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Joined: Wed Sep 25, 2019 12:16 am

Nonpolar and polar

Postby Jessica Tejero 3L » Sat Dec 07, 2019 12:01 pm

Whats the easiest ways to tell whether a molecule is polar or non-polar?

HuyHa_2H
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Re: Nonpolar and polar

Postby HuyHa_2H » Sat Dec 07, 2019 2:32 pm

You should see if the dipoles cancel out in the molecule. If they cancel, then it's nonpolar and if they don't then it's polar.

Bai Rong Lin 3I
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Re: Nonpolar and polar

Postby Bai Rong Lin 3I » Sun Oct 18, 2020 11:30 pm

Jessica Tejero 3L wrote:Whats the easiest ways to tell whether a molecule is polar or non-polar?

I believe it is based on the electronegativity of the molecules

Mehreen 2H
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Re: Nonpolar and polar

Postby Mehreen 2H » Sun Oct 18, 2020 11:38 pm

If the difference in electronegativity for the atoms in a bond is greater than 0.4, the bond is considered. If the difference in electronegativity is less than 0.4, the bond is essentially nonpolar. Sometimes you can tell from drawing out the molecule and looking at the charges and if its evenly spread out.

Jiapeng Han 3A
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Re: Nonpolar and polar

Postby Jiapeng Han 3A » Fri Oct 30, 2020 8:38 am

Firstly, you need to check if some of the atoms are more electronegative than others. Secondly, you need to see if the dipole cancels out. For example, CO2 has polar bonds, but the molecular is non-polar.

Aaina 1D
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Re: Nonpolar and polar

Postby Aaina 1D » Fri Oct 30, 2020 8:40 am

Polar molecules have an unequal sharing of electrons. For example, in the molecule H2O, O is more electronegative than H, making it attract more electrons. This gives them a partial negative charge, and hydrogen (H) a partial positive charge. The e- sharing is unequal, and therefore the molecule is polar. Non-polar molecules are usually symmetric in terms of sharing electrons.

DMaya_3C
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Re: Nonpolar and polar

Postby DMaya_3C » Fri Oct 30, 2020 1:03 pm

Does electronegativity have any connection with a molecule being polar or nonpolar?

Crystal Pan 1B
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Re: Nonpolar and polar

Postby Crystal Pan 1B » Fri Oct 30, 2020 1:19 pm

A polar covalent bond occurs when electrons are shared unequally, so if the difference in electronegativity is greater than or equal to 0.5, the bond is polar. A nonpolar covalent bond occurs when the atoms bonded together are of relatively similar electronegativies.

Yichen Fan 2E
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Re: Nonpolar and polar

Postby Yichen Fan 2E » Fri Oct 30, 2020 2:05 pm

Whether a bond is polar covalent or nonpolar covalent or iconic can be determined by the difference in electronegativity between the atoms. Typically less than 0.5 is nonpolar, between 0.5 and 2 is polar covalent, greater than 2 is ionic. The electronegativity value of elements can be found easily by searching it, usually the value follows its electron affinity. If you are trying to determine the polarity of a molecule, then the overall shape of that molecule also needs to be considered which I'm sure Dr. Lavelle will get into in future weeks.

jessicasilverstein1F
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Re: Nonpolar and polar

Postby jessicasilverstein1F » Sat Oct 31, 2020 11:36 am

to see if a bond is polar or nonpolar can be determined by the difference in electronegativity between the atoms. Determining if the dipoles cancel out, if they do then it is nonpolar and if they dont then it is polar

Karina Grover 1K
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Re: Nonpolar and polar

Postby Karina Grover 1K » Sat Oct 31, 2020 11:45 am

To determine polarity, you need to look at the electro-negativities of the atoms in the molecule. Electronegativity tends to increase from left to right across the periodic table, and from bottom to top of the periodic table. Two atoms with a fairly substantial difference in electronegativity such as oxygen and hydrogen (i.e. in a water molecule) yields polarity.

DavidTabib
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Re: Nonpolar and polar

Postby DavidTabib » Sat Oct 31, 2020 5:35 pm

Thanks for the help guys, this makes sense now!

Chinyere Okeke 2A
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Re: Nonpolar and polar

Postby Chinyere Okeke 2A » Sun Nov 01, 2020 10:45 am

I think to tell the difference between nonpolar and polar (there is a charge) you look at the relative electronegativity between the atoms, for example since C and H are close together on the periodic table they have similar electronegativities so a CH4 molecule would be nonpolar because there is not a significant charge.

Jaclyn Schwartz 2D
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Re: Nonpolar and polar

Postby Jaclyn Schwartz 2D » Sun Nov 01, 2020 11:04 pm

DMaya_3C wrote:Does electronegativity have any connection with a molecule being polar or nonpolar?

Yes it does! That's what cause polar bonds, the electronegativity difference cause there to be uneven sharing of electrons.

Morgan Gee 1F
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Re: Nonpolar and polar

Postby Morgan Gee 1F » Sun Nov 01, 2020 11:21 pm

For the most part, different biological elements have a large enough electronegativity to be polar. A notable exception is that a C-H bond is nonpolar. When there are larger molecules with more than just two elements, it becomes much more tricky and requires you to see if the molecule is "balanced". This occurs when there is an equal attraction to electrons in all directions. There can also be molecules that are amphipathic which are both polar and nonpolar such as fatty acids from biology.

Jarrett Sung 3B
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Re: Nonpolar and polar

Postby Jarrett Sung 3B » Sun Nov 01, 2020 11:23 pm

Polarity in molecules is based on the difference in electronegativity between bonded atoms. Typically, polar molecules will have polar bonds where the two atoms have vastly different electronegativities, so the electron isn't shared equally. However, nonpolar molecules can also have polar bonds, but tend to be symmetrical which cancels out the difference in polarity.

Dylan_Nguyen_3C
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Re: Nonpolar and polar

Postby Dylan_Nguyen_3C » Mon Nov 02, 2020 12:01 am

The difference in electronegativity between bonded atoms determines polarity. As the difference in electronegativity increases, the more polarized the distribution of electrons becomes. A way you can tell polarity is looking at the molecule; if for example a molecule has polar bonds but is symmetrical and the dipoles cancel, the molecule is non polar.


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