1. Polar Bonds and Molecules Chapter 8.4

2. Learning Objectives Be able to use electronegativity to identify polar vs. non-polar covalent bond Draw correct dipoles on a covalent bond Draw correct net dipole on a molecular compound

3. – 1.7 to 4.0: Ionic Bond – 0.3 to 1.7: Polar Covalent Bond – 0.0 to 0.3: Non-Polar Covalent Bond If the difference in electronegativity is between

4. Electronegativity Scale

5. Polar Covalent Bond vs Non- Polar Covalent Bond

6. Polar Covalent vs Non-Polar Covalent

7. Drawing Bond Dipoles: BF 3

8. Drawing Bond Dipoles: CH 3 OH

9. Net Dipole of Molecules Dipole – separation of charges within a molecule between two covalently bonded atoms. Net Dipole – When all the dipole vectors are summed to give one overall dipole.

10. Let’s Practice Get out your white boards … Show the polar bonds (  - and  +) and then predict the net dipole moment of the molecule. You’ll need to use the electronegativity chart on page 177 of your textbook. PF 3 - phosphorus trifluoride NH 3 - ammonia (nitrogen trihydride) CCl 4 – carbon tetrachloride BrF 5 - bromine pentafluoride