1. Hybridization
College Chemistry

2. VSEPR Theory How can I tell what molecular shape an atom is?
Geometry not considering lone pairs
Geometry considering lone pairs
How many single bonds off the central atom?

3. VSEPR Theory How can I tell what molecular shape an atom is?
Dashed line means these electrons are away from you
Wedged line means these electrons are towards you

4. VSEPR Theory How can I tell what molecular shape an atom is?
Bond Angle

5. VSEPR Theory Let’s try methane (CH4) Central atom? Valence Electrons?
Draw Bonds?
Lone pairs off central atom?
none
Molecular Geometry?
tetrahedral
Bond angle?
109.5

6. VSEPR Theory So let’s try ammonia(NH3) Central atom?
Valence Electrons? 5
Draw Bonds?
Lone pairs off central atom?
One pair
Molecular Geometry?
Trigonal pyramidal
Bond angle?
107

7. VSEPR Theory
Remember those double and triple bonds? We can draw those in VSEPR theory too
Only the first bond is counted for bonding purposes (i.e.: a double and triple bond is counted only once)
The first bond/single bond – sigma bond (s)
Second/third bond – pi bond (p)

8. VSEPR Theory Remember those double and triple bonds? Let’s try CO2
Central atom? C
Valence Electrons?
C – 4
Draw Bonds?
Lone pairs off central atom?
none
Molecular Geometry?
linear
Bond angle?
180
sigma pi

9. Hybridization
Hydridization – mix of several atomic orbitals (s and p subshells) to form hybrid oribals
Describes the type of bonds formed, which the VSEPR theory CANNOT do!!

10. 8.3
Hybridization
In methane, each of the four sp3 hybrid orbitals of carbon overlaps with a 1s orbital of hydrogen.

11. Hybrid Orbitals 8.3 Hybridization Involving Double Bonds
In an ethene molecule, two sp2 hybrid orbitals from each carbon overlap with a 1s orbital of hydrogen to form a sigma bond. The other sp2 orbitals overlap to form a carbon–carbon sigma bond. The p atomic orbitals overlap to form a pi bond. Inferring What region of space does the pi bond occupy relative to the carbon atoms?

12. Hybrid Orbitals 8.3 Hybridization Involving Triple Bonds
In an ethyne molecule, one sp hybrid orbital from each carbon overlaps with a 1s orbital of hydrogen to form a sigma bond. The other sp hybrid orbital of each carbon overlaps to form a carbon–carbon sigma bond. The two p atomic orbitals from each carbon also overlap. Interpreting Diagrams How many pi bonds are formed in an ethyne molecule?

13. Hybrid Orbitals sp3 – four things “attached” to central atom
sp2 - three things attached, double bonds
sp - two things attached, triple bonds
Let’s try some….
sp3
sp sp

14. Hybrid Orbitals
A few more…
sp2 sp