molecular geometry (vsepr theory) prem d. sattsangi christopher l. byers (programmer) © 2010 prem...
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Molecular Geometry(VSEPR theory)
Prem D. SattsangiChristopher L. Byers (programmer)
© 2010
Learning Molecular Geometry
The total number of bonds and unshared (non- bonded) electron pairs (E.P.) determine the electron domain around the central atom.
Bonds will be shown as solid lines.
Non-Bonded E.P. will be shown as balloons.
O
H H
E.G.
Trigonal Planar StructuresA = Central AtomX = Bonded Atom (or Non-Bonded E.P.)120° angles, sp2 hybridization
Molecular Geometry“Bent”
X
A
X
120°
X
A
X X
Molecular Geometry“Trigonal Planar”
AX
XX 120°
Top Views
Side View
In molecular geometry the orbitals are not shown.
Aluminum chloride AlCl3
Nitrate Ion NO3-
Nitrite Ion NO2-
Tetrahedral StructuresX
X
AX109.5°
A = Central AtomX = Bonded Atom (or Non-Bonded E.P.)109.5° angles, sp3 hybridization
Molecular Geometry“Trigonal Pyramidal”
Molecular Geometry“Bent”
X
X
AX X
107°
X
AX104.5°
Each Non-Bonded E.P. reduces the angle by 2.5°.
Methane CH4
Ammonia NH3
Water H2O
Trigonal Bipyramidal StructuresX
X
AX
XX 120°
90°
Axial
Equatorial
A = Central AtomX = Bonded Atom (or Non-Bonded E.P.)90° angle between Axial and Equatorial bonds120° angle between Equatorial bonds, sp3d hybridization
X
X
AX
X
Molecular Geometry“Seesaw”
Molecular Geometry“T-Shaped”
X
X
A
Molecular Geometry“Linear”
X
X
AX
The non-bonded E.P. occupies the equatorial position.
Phosphorus pentachloride PCl5
Sulfur tetrafluoride SF4
Chlorine trifluoride ClF3
Octahedral Structures
90°
A = Central AtomX = Bonded Atom (or Non-Bonded E.P.)90° angles, sp3d2 hybridization
Molecular Geometry“Square Pyramidal”
Molecular Geometry“Square Planar”
X
X
X
A
X
X
X
X
X
A
X
X90°
X
XA
X
X90°
X
Sulfur hexafluoride SF6
Bromine pentafluoride BrF5
Review Quiz 1Name the molecular geometry of the following compounds.
NO O
NO2
H
NH H
NH3
Trigonal Planar Tetrahedral
Trigonal PyramidalBent
OH H
H2O
Bent
F
BF F
BF3 sp2 hybrid
H
H
CH HCH4 sp3 hybrid
Review Quiz 2Name the molecular geometry of the following compounds.
Cl
Cl
PCl
ClCl
PCl5sp3d hybrid
Trigonal Bipyramidal Seesaw
Linear
F
F
SF
F
SF4
T-Shaped
F
F
Xe
XeF2F
F
ClF
ClF3
Review Quiz 3Name the molecular geometry of the following compounds.
F
F
F
S
F
F
F
SF6
sp3d2 hybridF
F
Br
F
F
F
BrF5
FXe
F
F
F
XeF4
Octahedral Square Pyramidal Square Planar
Trigonal Bipyramidal (has 5 electron domains)
# Bonds Non-Bond E.P. Geom.
5 0 Trig. Bipyr
4 1 Seesaw
3 2 T-Shaped
2 3 LinearCl
P
Cl
Cl
Cl
Cl
F
F
F
Cl
F
F
Xe
F
FF
F
S
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