1. Exceptions to octet rule
General Properties
Chapter 6 Honors Chem.
General Properties
Soluble in water
Insoluble in water
Conductive in sol’n
Chemical Bonding
Nonconductive in sol’n
Higher M.P.’s
Lower M.P.’s
IONIC...transfer
Lowers energy of system
Rationale:
COVALENT...sharing
Accompanied by:
Accompanied by:
Process (steps)
I.E
A Blend
E.A
How to tell
Pauling
L.E.
Polar Covalent… unequal sharing
Person Responsible
Electro- negativity
>1.7
0.0 – 0.3
differences
2-D Lewis Structures
Resonance
^and 3-D**
Guidelines
Count
d- d+
Connect
Exceptions to octet rule
Multiple Bonds
Polarity of bonds
Distribute

2. Multiple bonds count the same as single bonds
Honors Chem.
Molecular Shapes
dictated by
nonpolar
polar
(symmetrical)
(nonsymmetrical)
Polarity of Molecules V S E P R
Theory
shows
(when atom arrangements vary)
alence
air
isomerism
hell
**3-D Lewis Structures
lectron
epulsion
from this you
resonance
CH4
(when one bonding arrangement is insufficient)
NH3
H2O
can create
BF3
109.5° angles
107° angles
104.5° angle
120° angles
Example # of bonds** # of lone pairs EPA Shape Hybridization
CH4 4
SO2
tetrahedral
tet.
sp3
NH3 3 1
tet.
trig. pyramidal
sp3
H2O 2 2
tet.
bent
sp3
<120° angle
possible scenarios
BF3 3
trig. planar
trig. planar
sp2
SO2 2 1
trig. planar
bent
sp2
CO2 2
linear
linear sp
180° angle
Multiple bonds count the same as single bonds **

3. The polyatomic ion chlorate has the formula ClO3-
The polyatomic ion chlorate has the formula ClO3-. Give two pieces of information why this “molecule with a charge” exhibits covalent bonding.
1. It contains nonmetal parts that cling to each other via sharing of electrons.
2. The electronegativity difference between chlorine and oxygen is only 0.5 (polar covalent bond)
Draw the 2-D Lewis diagram to depict the features of this molecule like the sharing of electrons and what atom is bonded to what atom.
26 valence electrons O Cl O O

4. What is the total number of bonds and lone pairs around the central atom?
What is the Electron Pair Arrangement (EPA) of the electron pairs around the central atom in 3 dimensional space?
tetrahedral
What is the shape (geometry) of this molecule?
trigonal pyramidal
Draw the 3-D Lewis structure with this information O Cl O O

5. What is the total number of bonds and lone pairs around the central atom?
What is the Electron Pair Arrangement (EPA) of the electron pairs around the central atom in 3 dimensional space?
tetrahedral
What is the shape (geometry) of this molecule?
trigonal pyramidal
Draw the 3-D Lewis structure with this information
What is the bond angle between the Chlorine-Oxygen bonds?
What is the hybridization on the chlorine?
Are the bonds polar?
Yes!
sp3 Cl
Is this shape symmetrical?
d- d+ O O
No!
107° angles O

6. H Cl C C Cl H H Cl C C H Cl Cl H C C Cl H Analyze the molecule C2H2Cl2
As a 2-D Lewis Structure
As a 3-D Lewis Structure
Label bond angles
Describe the EPA on either carbon
Describe hybridization on either carbon
Draw another isomer as a 3-D Lewis Diagram
Does this molecule exhibit resonance? C C Cl H H
2-D structure Cl C C
EPA (on either carbon) = trigonal planar H Cl Cl H
isomer C C
120°(all around) Cl H
hybridization (on either carbon) = sp2
3-D structure
No resonace!!!!