VESPR THEORY

1. VSEPR Theory

2. explain the shapes of, and bond angles in, molecules by using
the qualitative model of electron-pair repulsion (including lone
pairs), using as simple examples BF3 (trigonal planar), CO2
(linear), CH4 (tetrahedral), NH3 (pyramidal), H2O (non-linear),
SF6 (octahedral), PF5 (trigonal bipyramidal)

3. What does the VSEPR states

4. VSEPR - Valance shell electron pair
repulsion
Electrons pair are arranged around the central atom in
such a way to minimise the repulsion between them

5. Case #1

6. Linear planar
180 degrees
bonded by 2 electron pairs
CO2, CS2 , HCN, BeF2

7. Case #2

8. Trigonal planar
120 degrees
bonded by 3 electron pairs
BF3 , AlCl3 , SO3 , NO3 -, CO3 2-

9. Case #3

10. Tetrahedral
109.5 degrees
bonded by 4 electron pairs
SiCl4 , SO4 2-, ClO4 -, NH4+
NH4+
L.P of electron got changed to bond pair so repulsion
decreases so angle slighty increase
NH3 + H+ → NH4+
107 109.5

11. Case #4

12. Trigonal Bipyramidal
120 and 90 degrees
bonded by 5 electron pairs
PCl5

13. Case #5

14. Octahedral
90 degrees
bonded by 6 electron pairs
SF6

15. Special Case #6

16. Trigonal pyramidal
107 degrees
bonded by 3 electron pairs and one lone pair
SiCl4 , SO4 2-, ClO4 -, NH4+
Due to high repulsion between the L.P
and B.P electrons, the bond angle slighty
decreases to 107 degrees

17. Special Case #7

18. Bent/V-shape/Angular
104.5 degrees
bonded by 2 electron pairs and 2 lone pair
OCl2 , H2S, OF2 , SCl2, H3O+, SO2
Since there are 2 L.P, so the maxi
repulsion taken place between
the L.P & L.P and L.P & B.P so
angle is reduced to 104.5