How do you prove polarity?

Question

How do you prove polarity?

Answer 1

Hmm, if my memory serves me right. A compound is polar when there is an unequal share of electrons, such as HBr or H2O

In compounds like I2 or Br2, there is an equal share of electorons and therefore those compounds are nonpolar.

From this, you might think that if the elements bound to each other are not identical, then the bond is polar.

However, be careful because a compound such as CH4 is also nonpolar because there is an equal pull from each Hydrogen onto the central Carbon atom.

In conclusion, you need to look not only at the elements bound, but also visualize the way they bind to prove polaity.  If the elements are identical, or there is an queal pull then its nonpolar. If the elements are different and the pull is unqual (2hydrogens pulling on 1oxygen) then its polar

Answer 2

(1) Using an arrow show the direction of polarity in each polar bond of the molecular shape. If the overall direction of polarity does not cancel out the molecule is polar.

(2) If you can imagine the molecular shape in 3D, the molecule is polar if the centers of partial charges do not coincide