Chemistry question on molecules..?

Question

How do you determine if a molecule is polar or non polar? I know that you can determine the polarity of the individual bonds associated within the entire molecule, but how can I say this whole molecule is polar/non polar?

Answer 1

Use the difference in electronegativity of the atoms to determine is the bond is nonpolar, polar, or ionic. Look at the geometry of the molecule. If you can isolate + and - ends the molecule is polar. If you cannot it is nonpolar.

Answer 2

1) if there are no polar bonds in the molecule, then the molecular is nonpolar

2) if there are polar bonds in the molecule, then you have to draw a Lewis structure for the molecule that shows the bonding AND the lone pairs of valence electrons so you can determine if the molecule is symmetric or not

if the molecule is symmetric, then it is nonpolar

if the molecule is not symmetrical, then it is polar

Answer 3

You can determine if something is polar or non-polar by looking at its shape.

Let's say, for example. H20.... h20 forms a V-Shape by itself....because the hydrogen molecules pull on the Oxygen molecule at a angle that doesn't cancel out the like forces, it is considered assymetrical and therefore polar.

Example:

___H
__/__\
O____O

If the shape has the *attractions* cancelling each other (meaning symmetric)...such as:

O=C=O

it is considered non polar