1. Chapter 8

2. Bond Polarity Nonpolar Covalent: Electrons pulled relatively equally
EN difference 00.4
Ex. H-H

3. Bond Polarity Polar Covalent Electrons pulled unequally
EN difference 0.51.9
More EN atom will attract electrons and have a slight negative charge
Ex. H-Cl

4. Bond Polarity Ionic Bond EN difference will be greater than 1.9
ALL ionic compounds will always have ionic bonds, no matter what the EN difference is
Ex. NaCl

5. Polar bonds but not a polar molecule?
Sometimes, a molecule can have polar bonds but be a nonpolar molecule
Ex. Water and Carbon Dioxide

6. Intermolecular Forces
Intermolecular attractions are weak attractions between groups. They are weaker than ionic or covalent bonds
Inter- among or between groups
Intra- inside or within

7. Van Der Waals Forces Dipole
Polar molecules are attracted to each other
Slightly negative region is attracted to slightly positive region of another molecule
Ex. HCl

8. Van Der Waals Forces Dispersion (London Dispersion)
Weakest of all forces
All polar and non polar molecules
Non polar molecules can bond to one another
Strength increases as the number of electrons increases

9. Hydrogen Bonding Strongest of all forces
Hydrogen is covalently bonded to fluorine, oxygen, or nitrogen (FON)
May be in the same molecule or nearby molecule

10. Bond Length Distance between centers of bonded atoms
Determined by X-ray diffraction of solids
Bond
# of electrons
Bond Order
Bond Strength
Bond Length
Single 2 1
Weakest
Longest
Double 4
Triple 6 3
Strongest
Shortest

11. Bond Energy

12. Calculate the Bond Energy
CO2
C2H4
PH3