1. Valence Shell Electron Pair Repulsion Theory: VSEPR
Molecular GeometrIES
Valence Shell Electron Pair Repulsion Theory: VSEPR

2. ELECTRONS & BONDS

3. Regions of Electron Density
ED: 4
4 Bonds
ED: 4
3 Bonds, 1 Pair
ED: 4
2 Bonds, 2 Pairs

4. MOLECULES EXIST IN 3 DIMENSIONS!
METHANE: TETRAHEDRAL

5. METHANE VS. AMMONIA METHANE AMMONIA ED BONDS LONE e- PAIRS BOND ANGLE
GEOMETRY

6. VSEPR Theory
THE GEOMETRY OF A MOLECULE IS DETERMINED BY ELECTROSTATIC REPULSIONS ABOUT THE CENTRAL ATOM:
BOND/LONE PAIR
(MORE REPULSION!)
BOND/BOND
(LESS REPULSION!)

7. MOLECULES EXIST IN 3 DIMENSIONS!
WATER: BENT

8. MOLECULAR GEOMETRIES

9. LET’S PRACTICE! TRY: SF4 SO42- PCl5 SO3
Predict the molecular geometries of the following compounds by determining the regions of electron density and the lone pairs about the central atom:
OF2 PF CS2 NSF
TRY:
SF4 SO PCl5 SO3

10. O XYGEN DIFLUORIDE

11. PHOSPHORUS TRIFLUORIDE

12. CARBON DISULFIDE