Transcript VSEPR Theory

Ch. 6 Bonding
6.5 VSEPR Theory and Molecular Shapes
VSEPR Theory
V alence
S hell
repulsion between pairs of
electrons around an atom
cause them to be as far
apart as possible
E lectron
P air
R epulsion
used to predict the
geometry of molecules
Molecular Shapes
diatomic molecules will always be linear
all other molecules can have different shapes based
on the number of charge clouds around the central
atom
charge clouds include:
Bond (single, double, & triple bonds count as 1 charge
cloud)
lone pairs
2 Charge Clouds
no lone pairs: linear
CO2
3 Charge Clouds
no lone pairs: trigonal planar
1 lone pair: bent
CH2O
SO2
4 Charge Clouds
no lone pairs: CH4
tetrahedral
1 lone pair: NH3
trigonal
pyramidal
4 charge clouds
2 lone pairs: H2O
bent
5 Charge Clouds
no lone pairs: trigonal
bipyramidal
PCl5
1 lone pair:
seesaw
SF4
2 lone pairs: ClF3
T-shaped
5 Charge
Clouds
3 lone pair: I3Linear
6 Charge Clouds
no lone pairs: SF6
1 lone pair:
octahedral
square pyramidal
SbCl52-
Cl
Cl
Cl
Sb
Cl
Cl
6 charge clouds
2 lone pairs: XeF4
square planar
3 lone pairs: ???
T-shaped
4 lone pairs: ???
linear
Here’s a summary:
You need
to know the
geometry
names and
the steric #
& lone
pairs that
go with
them.
You do not need to memorize all bond angles