Page 1 of 1

Nonpolar and polar

Posted: Sat Dec 07, 2019 12:01 pm
by Jessica Tejero 3L
Whats the easiest ways to tell whether a molecule is polar or non-polar?

Re: Nonpolar and polar

Posted: Sat Dec 07, 2019 2:32 pm
by HuyHa_2H
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.

Re: Nonpolar and polar

Posted: Sun Oct 18, 2020 11:30 pm
by Bai Rong Lin 3I
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

Re: Nonpolar and polar

Posted: Sun Oct 18, 2020 11:38 pm
by Mehreen 2H
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.

Re: Nonpolar and polar

Posted: Fri Oct 30, 2020 8:38 am
by Jiapeng Han 3A
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.

Re: Nonpolar and polar

Posted: Fri Oct 30, 2020 8:40 am
by Aaina 1D
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.

Re: Nonpolar and polar

Posted: Fri Oct 30, 2020 1:03 pm
by DMaya_3C
Does electronegativity have any connection with a molecule being polar or nonpolar?

Re: Nonpolar and polar

Posted: Fri Oct 30, 2020 1:19 pm
by Crystal Pan 1B
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.

Re: Nonpolar and polar

Posted: Fri Oct 30, 2020 2:05 pm
by Yichen Fan 2E
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.

Re: Nonpolar and polar

Posted: Sat Oct 31, 2020 11:36 am
by jessicasilverstein1F
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

Re: Nonpolar and polar

Posted: Sat Oct 31, 2020 11:45 am
by Karina Grover 1K
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.

Re: Nonpolar and polar

Posted: Sat Oct 31, 2020 5:35 pm
by DavidTabib
Thanks for the help guys, this makes sense now!

Re: Nonpolar and polar

Posted: Sun Nov 01, 2020 10:45 am
by Chinyere Okeke 2A
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.

Re: Nonpolar and polar

Posted: Sun Nov 01, 2020 11:04 pm
by Jaclyn Schwartz 2D
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.

Re: Nonpolar and polar

Posted: Sun Nov 01, 2020 11:21 pm
by Morgan Gee 1F
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.

Re: Nonpolar and polar

Posted: Sun Nov 01, 2020 11:23 pm
by Jarrett Sung 3B
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.

Re: Nonpolar and polar

Posted: Mon Nov 02, 2020 12:01 am
by Dylan_Nguyen_3C
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.