Download Chapter 9 Diatomic Molecular Orbitals and

Leader: Ryan Gale
Course: Chem 177
Instructor: Miller/Bonaccorsi
Supplemental Instruction
Date: 10/30/12
Iowa State University
1) Propylene, C3H6, is a gas that is used to form the important polymer called
polypropylene. Its Lewis structure is
H HH
| | |
H-C=C-C-H
|
H
a.) What is the total number of valence electrons in the propylene molecule?
Chapter 9 Diatomic Molecular
Orbitals and Multiple Bonds
b.) How many valence electrons are used to make σ bonds in the molecule?
c.) How many valence electrons are used to make π bonds in the molecule?
d.) How many valence electrons remain in nonbonding pairs in the molecule?
2) Draw an energy diagram for the process of two atoms of boron bonding together. Show
where the bonding molecular orbitals fit and where the anti-bonding orbitals fit in the
diagram. Make sure to show the atomic orbitals in the correct energy level as well.
Label which molecular orbital is sigma and which is sigma star.
Supplemental Instruction
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3) Draw a similar energy diagram, now for diatomic carbon.
4) Now draw another similar energy diagram, but instead for one atom of oxygen bonding
with a positively charged oxygen cation.
5) Now calculate the bond orders from problems 2, 3, and 4. Remember, bond order = (# of
bonding electrons - # of antibonding electrons)/2. Also, explain what type of magnetic
behavior each molecule has (i.e. diamagnetic, paramagnetic, or not magnetic)B.
a) B2
b) C2
c)O2+