Determining if a molecule is polar or non polar

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

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Blanca Cervantes
Posts: 17
Joined: Wed Nov 21, 2018 12:18 am

Determining if a molecule is polar or non polar

Postby Blanca Cervantes » Fri Nov 15, 2019 11:18 pm

When determining if a molecule is polar or non polar on the test, is it expected of us to know the electronegativity values of the elements in the given molecules?

madijohnson_4A
Posts: 40
Joined: Fri Aug 30, 2019 12:18 am

Re: Determining if a molecule is polar or non polar

Postby madijohnson_4A » Fri Nov 15, 2019 11:29 pm

I don't think we need to memorize exact electronegativities, but knowing the trends in electronegativity would probably be helpful to determine what bonds would be polar vs nonpolar. In general, the electronegativity increases as you move diagonally up and to the right of the periodic table.

Michelle Chan 1J
Posts: 50
Joined: Thu Jul 25, 2019 12:16 am

Re: Determining if a molecule is polar or non polar

Postby Michelle Chan 1J » Fri Nov 15, 2019 11:33 pm

I don't think we need to know exact values, but we should know generally which atom is the most electronegative in relation to others in the molecule.

Melvin Reputana 1L
Posts: 55
Joined: Sat Aug 17, 2019 12:16 am

Re: Determining if a molecule is polar or non polar

Postby Melvin Reputana 1L » Sat Nov 16, 2019 12:30 am

We're not expected to know the exact electronegativity values, instead we should know the periodic trend for electronegativity which follows the same trends as ionization energy and electron affinity. Also, the questions we'll be given will probably make the electronegativity differences between two atoms be obvious from the trends which will help us find the dipole moment.

Kaitlyn Jang 1F
Posts: 45
Joined: Sat Aug 17, 2019 12:16 am

Re: Determining if a molecule is polar or non polar

Postby Kaitlyn Jang 1F » Sat Nov 16, 2019 1:09 am

I don't think we have to know exact values of electronegativity. However, the periodic table should tell us the polarity (or lack thereof) of molecules based on the trends of electronegativity.

Maya Gollamudi 1G
Posts: 60
Joined: Thu Jul 25, 2019 12:15 am

Re: Determining if a molecule is polar or non polar

Postby Maya Gollamudi 1G » Sat Nov 16, 2019 11:44 am

We don't have to determine polarity of the molecule using exact electronegativity values. We can determine if a bond is polar/nonpolar using trends from the periodic table. If polar bonds cause dipoles and don't cancel out in a molecule, it will be polar. If the dipoles do cancel out, the molecule will be nonpolar.

Rodrigo3H
Posts: 62
Joined: Sat Jul 20, 2019 12:16 am

Re: Determining if a molecule is polar or non polar

Postby Rodrigo3H » Sat Nov 16, 2019 2:26 pm

I don't think it will be necessary to know specific electronegativity numbers, but there are some cases in which you can use the the trends of electronegativity to determine if the molecule has a net dipole moment. If it does, it will be polar. If not then it will be non polar.

805373590
Posts: 56
Joined: Wed Sep 11, 2019 12:17 am

Re: Determining if a molecule is polar or non polar

Postby 805373590 » Sat Nov 16, 2019 2:33 pm

when determining the polarity we only need to take into account the electronegativity trends in the periodic table, therefore, don't need to memorize exact values.

faithkim1L
Posts: 65
Joined: Fri Aug 09, 2019 12:17 am

Re: Determining if a molecule is polar or non polar

Postby faithkim1L » Sat Nov 16, 2019 3:17 pm

We don't have to memorize the electronegativity chart. It's easier to use the net dipole to figure out if the molecule is polar or not. For example, for CH3Cl, there is a net dipole towards the chlorine atom, making the whole molecule. However, for CH4, there is no net dipole which makes the molecule non polar.

PGao_1B
Posts: 50
Joined: Sat Jul 20, 2019 12:15 am

Re: Determining if a molecule is polar or non polar

Postby PGao_1B » Sat Nov 16, 2019 4:30 pm

When determining if a molecule is polar or non polar on the test, it is not expected of us to know the electronegativity values of the elements in the given molecules. Just know the periodic trends for electronegativity and you should be fine.


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