1) Use your white board to draw the
Lewis structure for ozone, O3.
2) What does the word hybridization
mean? Use your own words.
While you are doing warm up I will
come around and check HW #24.
(except 4th period)
A resonance structure is a structure
that occurs when it is possible to draw
two or more valid electron dot structures.
In the case of ozone, neither structure
actually exists, but rather the actual
bonding is an average of the two
structures.
Definition of hybridization ….
- Learn what a sigma bond looks like
- Learn what a pi bond looks like
-Understand the concept of orbital hybridization and
how it changes the bonding in an atom such as carbon
When two atomic orbitals
combine to form a bond
along the axis between two
atoms … we call it a sigma
bond
(s)
When two “p” orbitals combine side by
side we say they overlap to form a pi (P)
bond
Pi bonds exist when we have double and
triple bonds
Single bond – 1 sigma bond
Double bond – 1 sigma and 1 pi bond
Triple bond – 1 sigma and 2 pi bonds
The electron structure of a carbon atom
can be written as:
Based on this model, we would predict that
carbon atoms should form two covalent
bonds??!!
Instead carbon atoms almost
always form 4 bonds.
Why????
Hybridization
Regular Carbon Aufbau Diagram
Hybridized Carbon Aufbau Diagram
hybridization
1 s + 3 p = 4 sp3
(All 4 orbitals are now equal at the 2nd
energy level)
Electrons must be distributed among the new orbitals.
Since these hybrid orbitals are equal in energy, the
electrons must distributed according to Hund’s Rule.
4
3
sp
orbitals
4 sp3 orbitals bond with
4 hydrogen atoms - methane
Overlap here
is known as
sigma bond
sp3 carbon
Let’s predict what sp2
hybridization around a carbon
might look like?
Take out your
white boards
2
sp
hybridization
2
sp
hybridization
carbon double bond - ethene
Can you predict sp
geometry around a carbon?
sp hybridization
sp hybridization
carbon triple bond - acetylene
sp hybridization
carbon triple bond - acetylene
234-236 in your text
discusses these examples
Summary
sp3 hybridization involves
single-bonded carbon
sp2 hybridization involves
double-bonded carbon
sp hybridization involves
triple-bonded carbon