VSEPR

1. VSEPR

VSEPR - Valence shell electron pair repulsion theory.

Is a model used to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms

  1. Draw a lewis structure.
  2. Count the nuber of electron clouds, surounding the central atom.
  3. Predict the geometry with electron pairs.
  4. Ignore lone pair and predict the molecular geometry



Practice


1. CO2 - Linear
Valence = 4 + 6*2 = 16
Needed = 8*3 = 24
Shared = 24 - 16 = 8

Bonds = 8/2 = 4
Lona pairs = 16 - 8 = 8; 8/2 = 4
2. BH3 - Trigonal Planar
3. BH2(-) - Bent
4. CH4 - Tetrahedral
5. NH3 - rigonal Pyramidal
6. H2O - bent

2. VSEPR Bond Angels




2. VSEPR Examples