Polar and Nonpolar

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Aimee Alvarado 3J
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Polar and Nonpolar

Postby Aimee Alvarado 3J » Sun Nov 29, 2020 11:39 pm

I usually know if a molecule is polar or nonpolar depending on if there is an unequal or equal sharing of electrons, but would I need to do more to make sure?

Taha 2D
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Re: Polar and Nonpolar

Postby Taha 2D » Sun Nov 29, 2020 11:40 pm

Depends on their shape as well and if the dipoles cancel or not

Susan Chamling 1F
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Re: Polar and Nonpolar

Postby Susan Chamling 1F » Sun Nov 29, 2020 11:55 pm

It helps to take into account the 3D shape of the molecule rather than just the Lewis structure, as the Lewis structure may lead us to believe it is nonpolar when it is actually polar, and vice versa. Sometimes I will look at the symmetry of the forces acting on the molecule, because if it is symmetrical it is most likely nonpolar since the forces cancel out.

Sheryl Ocampo 1D
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Re: Polar and Nonpolar

Postby Sheryl Ocampo 1D » Sun Nov 29, 2020 11:57 pm

The symmetry of the molecule also plays a role in polarity as the partial charges could cancel each other out

Astha Patel 2J
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Re: Polar and Nonpolar

Postby Astha Patel 2J » Sun Nov 29, 2020 11:59 pm

The shape of the molecule can show whether dipoles are positioned to cancel each other out.

alexandralopez 3F
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Re: Polar and Nonpolar

Postby alexandralopez 3F » Sun Nov 29, 2020 11:59 pm

You have to take into account the shape and see what the pull is like (if the dipoles cancel)

Kushaal Madadi 2F
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Re: Polar and Nonpolar

Postby Kushaal Madadi 2F » Mon Nov 30, 2020 12:02 am

It is important also to consider whether the shape of the molecule and the arrangement of the atoms causes the dipoles to cancel!

Fernanda Olvera 3D
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Re: Polar and Nonpolar

Postby Fernanda Olvera 3D » Mon Nov 30, 2020 12:03 am

I agree, ^ the shape and dipoles are taken into account to determine if it is polar/nonpolar.

Teti Omilana 1G
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Re: Polar and Nonpolar

Postby Teti Omilana 1G » Mon Nov 30, 2020 12:54 am

You also can draw the lewis structure for the molecule and look for asymmetry. If it is asymmetrical, it's polar and if it's symmetrical it's non- polar.

Sam Wentzel 1F 14B
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Re: Polar and Nonpolar

Postby Sam Wentzel 1F 14B » Mon Nov 30, 2020 1:11 am

Yes. You should memorize which molecular shapes are symmetrical, and thus non-polar assuming that the dipoles cancel, and which one's are not. Symmetrically shaped molecules will tend to be nonpolar, asymmetrically shaped molecules will tend to be polar. Hope this helps!

Gabriel Nitro 1E
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Re: Polar and Nonpolar

Postby Gabriel Nitro 1E » Mon Nov 30, 2020 8:29 am

Hi,

You should also take into account the shape of the molecule as the asymmetry/symmetry may cancel out polar bonds.

Hope this helps! :)

105618850
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Re: Polar and Nonpolar

Postby 105618850 » Tue Dec 01, 2020 10:54 am

You would also need to consider if the dipole moments, if there are any, cancel each other out.

Jordan Tatang 3L
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Re: Polar and Nonpolar

Postby Jordan Tatang 3L » Tue Dec 01, 2020 11:06 am

I usually draw the dipole moments to see if they cancel or not.

Charlotte Adams 1A
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Re: Polar and Nonpolar

Postby Charlotte Adams 1A » Tue Dec 01, 2020 1:56 pm

Drawing the shape of the molecule and the dipole moments will help because it will show if the dipole vectors cancel out.

Jasraj Parmar 3H
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Re: Polar and Nonpolar

Postby Jasraj Parmar 3H » Tue Dec 01, 2020 8:48 pm

You have to look at the shapes and see if the dipole force cancel each other out. If they cancel out each other than it is non-polar. If they don't cancel out they are polar.

Adrienne Yuh 2B
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Re: Polar and Nonpolar

Postby Adrienne Yuh 2B » Tue Dec 01, 2020 10:14 pm

I like to draw out the figure and arrows pointing in the dipole directions. Memorizing what cancels what is really helpful.

Nancy Yao
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Re: Polar and Nonpolar

Postby Nancy Yao » Wed Dec 02, 2020 5:22 am

The dipoles are like vectors and sometimes they cancel out each other.

Annette Fishman
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Re: Polar and Nonpolar

Postby Annette Fishman » Thu Dec 03, 2020 1:30 pm

It becomes way easier when you draw the molecule and draw out the vectors to signify the dipoles! If they cancel out, the molecule is nonpolar.

Edwin Liang 1I
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Re: Polar and Nonpolar

Postby Edwin Liang 1I » Fri Dec 04, 2020 5:43 pm

Drawing the molecule and seeing whether there is a difference in dipoles helps too

Brenda Silva 1B
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Re: Polar and Nonpolar

Postby Brenda Silva 1B » Fri Dec 04, 2020 10:28 pm

The shape of the molecule and the difference in dipoles are also important to figure out whether a molecule is polar or non-polar. If the dipole forces cancel out then the molecule is non-polar.

Allan Nguyen 2G
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Re: Polar and Nonpolar

Postby Allan Nguyen 2G » Fri Dec 04, 2020 10:36 pm

Don't forget that a molecule can have polar bonds but can still be a nonpolar molecule due to its shape.

Margaret Xu 3C
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Re: Polar and Nonpolar

Postby Margaret Xu 3C » Sat Dec 05, 2020 12:39 pm

In order to consider if a molecule is polar or nonpolar, I always draw the Lewis structure first to see if the dipoles cancel out of it there are lone pairs.

Rose_Malki_3G
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Re: Polar and Nonpolar

Postby Rose_Malki_3G » Sat Dec 05, 2020 2:08 pm

Check to see if the dipoles cancel it. If they do, then the species is non polar and if they do not cancel out, the species is polar.

Emma Ide 2E
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Re: Polar and Nonpolar

Postby Emma Ide 2E » Sat Dec 05, 2020 2:17 pm

The shape can indicate if the dipoles cancel or not. Polar molecule's dipoles do not cancel.

Hailey Qasawadish 2J
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Re: Polar and Nonpolar

Postby Hailey Qasawadish 2J » Sat Dec 05, 2020 5:05 pm

I also like to see what the shape is in order to determine if it is polar or nonpolar. A lot of times, you can determine polarity by looking at if there are lone pairs or not. If there are lone pairs, it is usually polar.

Morgan Gee 3B
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Re: Polar and Nonpolar

Postby Morgan Gee 3B » Sat Dec 05, 2020 6:11 pm

Understanding the 3D model of the lewis structure is important too, as 2D images may be misleading. A common example is the linear molecular geometry from a trigonal bipyramidal electron geometry (AX2E3). While it may appear to be polar because of the asymmetrical lone pairs, it is still considered to be a polar molecule.

CesarLec1
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Re: Polar and Nonpolar

Postby CesarLec1 » Sun Dec 06, 2020 1:32 am

A good thing to do if you have time is to draw the lewis structure of the formula and check to see if the bonds are polar and nonpolar to see if it all cancels out. If the central atom however, it surrounded by atoms that are all the same in symmetrical positions then all the polarity should cancel out.

Jeremy Wei 2C
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Re: Polar and Nonpolar

Postby Jeremy Wei 2C » Sun Dec 06, 2020 9:17 pm

Hi, what I normally do is that I draw out the 3D structure of the molecule and seeing if the dipole moments cancel out.

Algernon Jackson 2l
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Re: Polar and Nonpolar

Postby Algernon Jackson 2l » Sun Dec 06, 2020 9:21 pm

You have to also look at the shape and the dipoles.


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