Vsepr Lab

Molecular Geometry

A. Natural Orientation of Volumes about a Central Point.

You will need 20 round balloons for this experiment. Join them together as indicated in the Balloon Arrangement column and then describe the shape in the space provided.

Balloon Arrangement Description of the Shape
Two-Balloon Set Linear
Three-Balloon Set Trigonal Planar

Four-Balloon Set
Tetrahedral

Five-Balloon Set
Trigonal Bipyramidal

Six-Balloon Set
Octahedral

B. Valence Shell Pairs: Single Bonds

Fill in the table below for the corresponding compounds. Reference the tables provided in the introductory comments for Lab #16 VSEPR Theory.

Molecular
Shape Number of Bonds
About Central Atom Shape
Description
BF3 3 Trigonal planar
BeCl2
2 Linear
CH4
4 Tetrahedral
PF5
5 Trigonal bipyramidal
SF6
6 Octahedral

C. Valence Shell Pairs: Single Bonds and Non-Bonding electron pairs

Fill in the table below for the corresponding compounds. Reference the tables provided in the introductory comments for Lab #16 VSEPR Theory.

Molecular
Formula Number of Bonds and
Non-Bonding Pairs Shape
Desrciption
NF3 3,1 Trigonal pyramidal
H2S
2,2 Bent
H3O+
3,1 Trigonal pyramidal
PH3
3,1 Trigonal pyramidal
ClO2
2,1 Bent

D. Valence Shell Pairs: Single and Double Bonds and Non-Bonding electron pairs

Fill in the table below for the corresponding compounds. The shapes and other information on pages three and four of your lab will be helpful.

Formula Number of Bonds and
Non-Bonding Electron Pairs Shape
Description
CO32- 3,0 Trigonal planar
SO2
2,1 Bent
H2CO
3,0 Trigonal planar
SO3
3,0 Trigonal planar
SO32-
3,1 Trigonal pyramidal
NO2-
2,1 Bent
PO33-
3,1 Trigonal