Polar Bonds and Molecules Chapter 8.4

1
Polar Bonds and MoleculesChapter 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
If the difference in electronegativity is between

• 1.7 to 4.0 Ionic Bond
• 0.3 to 1.7 Polar Covalent Bond
• 0.0 to 0.3 Non-Polar Covalent Bond

4
Electronegativity Scale
5
Polar Covalent Bond vs Non-Polar Covalent Bond
6
Polar Covalent vs Non-Polar Covalent
7
Drawing Bond Dipoles BF3
8
Drawing Bond Dipoles CH3OH
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
Lets Practice
Get out your white boards
Show the polar bonds (d- and d) and then
predict the net dipole moment of the molecule.
Youll need to use the electronegativity chart on
page 177 of your textbook.
PF3 - phosphorus trifluoride NH3 - ammonia
(nitrogen trihydride) CCl4 carbon
tetrachloride BrF5 - bromine pentafluoride