Catalyst
Quantum FTW
Lecture 2.6 – Orbital Hybridization
Today’s Learning Targets
• LT 2.7 – I can explain how the overlapping of
orbitals with unpaired electrons leads to the creation
of covalent bonds and hybrid orbitals. I can explain
how sp, sp2, and sp3 orbitals are created and identify
a compound as containing one of these types of
hybridization.
Valence – Bond Theory
• While the discussions we have had about bonding
has been correct, how can we explain this using
quantum mechanics?
• Valence Bond Theory – Atoms bond when electron
densities are concentrated between the two atoms
nuclei. Bonding occurs when valence orbitals of
each atom overlap.
Quick Write
• Draw the Lewis structure for CF4. Predict the
electron domain geometry and the molecular
geometry of the compound.
Consider Carbon…
• Carbon’s valence electron configuration looks like:
Consider Carbon…
• If these form bonds with fluorine as predicted, then
3 of the bonds would have a higher energy than the
4th bond in the s orbital.
• The s and p orbitals “mix” in order to form new
orbitals that have equal energy
• They form sp3 orbitals that allow for bonding to
occur
Consider Carbon…
Orbital Hybridization
• Hybrid Orbitals – The orbitals of an atom can “mix”
to form new shapes
• These orbitals have a new energy level that is a
mixture of the two old energy levels.
3
sp
Hybrid Orbitals
• Occur when 3 p orbitals and 1 s orbital mix
• The 4 sp3 orbitals then arrange themselves such that
a tetrahedral shape is formed.
sp Hybrid Orbitals
• Form when the central atom mixes 1 s and 1 p
orbital to form 2 sp hybrid orbitals.
• Arranged in a linear shape and able to form 2 new
bonds
• INSERT BeF2 PICTURE
2
sp
Hybrid Orbitals
• Occur when 2 p and 1 s orbital mix to form new
shapes
• Hybrid orbitals arrange in a trigonal planar shape
and 3 new bonds can form
Molecules with Lone Pairs
• Central atoms often have lone pairs on them.
• These electron pairs are put in their own hybrid
orbitals.
• Example: H2O
Quick Way to Remember
Number of Hybrid Orbitals
Number of Lone Pairs
and/or Bonds for Central
Atom
Hybridization
2
sp
3
sp2
4
sp3
Class Example
• Determine the orbital hybridization of the central
atom for NH2 –
Table Talk
• Determine the orbital hybridization for SO32–
3
dsp
and
2
3
d sp
Hybridization
• For compounds with expanded Octets, d orbitals are
hybridized.
Number of Lone Pairs
and/or Bonds for Central
Atom
Hybridization
5
dsp3
6
d2sp3
White Board Races
Question 1
• What is the hybridization of the carbon atom in
CF4?
Question 2
• What is the hybridization of the central atom in BI3?
Question 3
• What is the hybridization of the central atom in
H2O?
Question 4
• What is the hybridization of the central atom in
NH3?
Question 5
• What is the hybridization of the central atom in
CO32-?
Question 6
• What is the hybridization of the central atom in SF6?
Closing Time
• Finish reading Chapter 9 and corresponding problems
• Pre – Lab for Lab 3 due start of class Thursday/Friday
• Lab questions for Labs 2 and 3 due next Wednesday