VSEPR Theory and Molecular geometry

VESPR definition

The Valence Shell Electron Pair Repulsion (VSEPR) theory is a model used to predict the geometry of individual molecules based on the repulsion between their electron pairs.

Tetrahedral

Atom with 4 sigma bonds

What is the bond angle for a tetrehedral?

109.5 degrees

Trigonal pyrmidal 

3 sigma bonds and 1 unshared pair 

-smaller because unshared electron pairs exert more repulsion than shared pairs 

Bond angle for trigonal pyramidal

107 degrees

Bent structure 

-2 sigma bonds 

-2 unshared pairs 

Bond angle of bent structures

104.5 degrees

Trigonal planar 

3 sigma bonds 

bond angle for trigonal planar

120 degrees

Angular

2 sigma bonds

1 unshared pair

-117 degrees

Linear bonds 

2 sigma bonds

180 degrees

Trigonal bypyrmidal

-90 and 120 degrees

-5 sigma bonds

octahedral

-6 sigma bonds

-90 degrees