Determining if a molecular is polar/np based on dipoles

[Crystal Odipo 1F]

From one of the lectures we concluded that CHCL3 is polar, because the dipole moments do not cancel based on the arrows we drew. Without the use of arrows how do we know if dipoles cancel or not?

[HannahRobinson3L]

Using the arrows is usually the best method of determining if a molecule is polar or nonpolar, but you also have to account for the geometry of the molecule. For example, if you just draw the lewis structure of H2CCl2, it will be a tetrahedral. If you draw the chlorines opposite of each other, it may look like the arrows cancel out, but they don't because in 3d space, they aren't directly opposite of each other.

[Isabella Cortes 2H]

I found that using arrows to draw out the dipole moments is the best way of determining if a molecule is polar or nonpolar because it is the one way to find out for sure if the dipoles will cancel out since you can also look at the molecule's structure as well.

[Emma_Barrall_3J]

You can use electronegativity values. So if the atoms bonded to the central atom have different electronegativities, depending on shape, the molecules is polar.