polar and non polar

[Anna Turk 1D]

Can someone please explain how to know if a molecule is polar or non polar? Thanks!

[rachelcameron2E]

A molecule is polar if there is a net dipole moment, meaning if there are partial positive and negative charges that do not cancel out on the molecule. H2O is polar because the dipole moment for both bonds is in the direction of oxygen, so they do not cancel out. Oxygen is slightly negative due to its high electronegativity pulling the electrons close to it, and hydrogen is slightly positive. In contrast, CCL4 is nonpolar. CCl4 has a tetrahedral shape, and when looking at the individual bonds between C and CL, we can see that the more electronegative CL will have a slightly negative charge and C will have a slight positive. However, when looking at the molecule as a whole, we can see that dipole moments are all pointing in opposite directions, so they will cancel out and the molecule is nonpolar. In sum, to see if a molecule is polar, you need to look at the dipole moments of the bonds in the molecule -- if they cancel out the compound is nonpolar and if they don't it's polar. I hope this helps!

[505706331]

a non polar molecule is a molecule where the dipole moments in the molecule all cancel out, usually there would be the same atom all around and the center atom doesn't have any lone pairs. a polar molecules is a molecule where the dipole moments do not cancel out so there will be a net dipole moment pointing towards one direction.

[Alyssa Cua 2J]

Can someone please explain how to know if a molecule is polar or non polar? Thanks!

Hi Anna!
In a nonpolar molecule, the dipole moments cancel out so there is an even electron distribution. For a polar molecule, however, there is a net dipole moment, meaning that one end is negatively charged, and the other is positively charged. Hope this helped!

[305607822]

Look at the overall dipole moment, if it doesn't cancel out meaning if there is a force pulling the electrons one way or another, there's a net charge within the molecule. So it would be polar.

[ElizabethKarlin2E]

If a molecule is polar, that means the dipole moments don't cancel out, so there is a variance of the charges in the molecule.

[Anna Turk 1D]

If a molecule is polar, that means the dipole moments don't cancel out, so there is a variance of the charges in the molecule.

Thank you! How do you figure out which way the dipole moment is going?

[Vashe Sundar 3H]

There are different ways to determine polarity. However, the most common/useful is drawing out the molecule w/ its dipoles. If the dipoles cancel each other out completely, then the molecule is non-polar. If not, then it's polar.