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.

sp3 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

sp2 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

OrbitalsNumber 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 SO3

2–

dsp3 and d2sp3 Hybridization

• For compounds with expanded Octets, d orbitals are hybridized.

Number of Lone Pairs and/or Bonds for

Central AtomHybridization

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 CO3

2-?

Question 6

• What is the hybridization of the central atom in SF6?

Closing TimeClosing 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