Chemistry
Name___________________
Date_________Period______
VSEPR Activity
Introduction
VSEPR Theory allows us to determine the geometry of molecular compounds. It is based on the simple idea that
negatively charged electron pairs (whether bonded or non-bonded) will repel one another and that his repulsion will be smallest
when the pairs are farthest apart. The geometry of a molecule depends on the number of groups of electrons that surround the
central atom. Single bonds, double bonds, and triple bonds, and non-bonded loan pairs are all examples of electron groups.
However, these groups repel on another differently as outlined below:
Lone Pair-Lone Pair
>
Lone Pair-Bonded Pair
>
Bonded Pair-Bonded Pair
Greatest Repulsion----------------------------------------------------------------------- Smallest Repulsion
Instructions
This is a two part activity. In the first part of the activity you will be filling in the tables below. In the second part of
this activity you will use balloons to show the shape of each molecule and make a sketch of the molecular geometry. Once you
have arranged the balloons in the shape of the molecule and have drawn your sketch, you must get your teacher’s initials.
Molecule
CH4
NH3
H2O
HF
# of
valence
electrons
in
molecule
# of
valence
electrons
around
the
central
atom
# of
single
bonds
on
central
atom
# of
double
bonds
on
central
atom
# of
triple
bonds
on
central
atom
# of
lone
pairs on
central
atom
Total #
of
electron
groups
on
central
atom
Name of
geometry
of
electron
pairs
Name of
molecular
geometry
Initials
H2S
HCl
PH3
SiH4
SF4
IF5
BrF3
SCl6
NO
CO2
H2CO
HCN