1. III. Molecular Polarity
Molecular Structure
III. Molecular Polarity

2. + - A. Dipole Moment H Cl Direction of the polar bond in a molecule.
Arrow points toward the more e-neg atom.
H Cl + -

3. B. Determining Molecular Polarity
Depends on:
dipole moments
molecular shape

4. B. Determining Molecular Polarity
Nonpolar Molecules
Dipole moments are symmetrical and cancel out.
BF3 F B

5. B. Determining Molecular Polarity
Polar Molecules
Dipole moments are asymmetrical and don’t cancel .
H2O H O
net
dipole
moment

6. B. Determining Molecular Polarity
Therefore, polar molecules have...
asymmetrical shape (lone pairs) or
asymmetrical atoms
CHCl3 H Cl
net
dipole
moment