Polar Molecules

Type A

(same atoms e.g O2, Cl2 …)

In _____, the bonds between ____ are non-polar as there is no difference in electronegativity. There are no bond dipoles so ____ is non-polar.

Type B

(2 different atoms, symmetrical e.g. CO2, BH3, CCl4 …)

In ____, the bonds between ____ + ____ are polar due to a difference in electronegativity. The ____ shape is symmetrical and so the bond dipoles can cancel. Thus, ____ is non-polar

Type C

(2 different atoms, unsymmetrical e.g. H2O, NH3 …)

In ____, the bonds between ____ + ____ are polar due to a difference in electronegativity. The ____ shape is unsymmetrical and so the bond dipoles can not cancel. Thus, ____ is polar.

Type D

(3 different atoms, symmetrical e.g. HCN, CHCl3, CH2Cl2 …)

In ____, the bonds between ____ + ____ and ____ + ____ are polar due to differences in electronegativity. Although the ____ shape is symmetrical, the bond dipoles are unable to cancel as they are different sizes. Thus, ____ is polar.

Symmetrical

• linear (2 regions)

• trigonal planar

• tetrahedral

Unsymmetrical

• linear (4 regions)

• trigonal pyrimidal

• bent (2 or 3 regions)