Molecular Geometry Ac
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Transcript of Molecular Geometry Ac
• I can describe the VSEPR theory• I can determine the VSEPR model of a given
molecule• I can predict the shape of a molecule using
VSEPR theory
Learning Targets
• The properties of molecules depend not only on the type of bonding but also on molecular geometry or the shape of the molecule.
• There are two theories used to predict molecular geometry: VSEPR theory (we will discuss) and hybridization (we will not discuss)
Molecular Geometry
• VSEPR – Valence Shell Electron Pair Repulsion• Theory is used to predict the shape of
molecules. • This theory is based on the idea that pairs of
electrons surrounding an atom repel each other causing the electron pairs to be as far apart from each other as possible.
VSEPR Theory
• The Lewis structure is used to determine the VSEPR model of the molecule.
• The following symbols are used for the VSEPR model
VSEPR Theory
A Central Atom
B Bonded Atom
E Lone Pair
Symbols
• The VSEPR model is used to determine the geometry and bond angles of the molecule
VSEPR Models
VSEPR Model Geometry Bond Angle
AB Linear 180o
AB2 Linear 180o
AB2E Bent 120o
AB3 Trigonal Planar 120o
AB2E2 Bent 105o
AB3E Trigonal Pyramidal 107o
AB4 Tetrahedral 109.5o
Other VSEPR Models
VSEPR Model Geometry
AB5 Trigonal Bypyramidal
AB4E Seesaw
AB3E2 T-Shaped
AB6 Octahedral
AB5E Square Pyramidal
AB4E2 Square Planar
AB5 Trigonal Bypyramidal
VSEPR Models
• Phosphorus Trichloride
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
• PCl3
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
• PCl3
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
P ClCl
Cl..
.
.
.
...
. .
. .
. . . .
. .
. .
• PCl3
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
P ClCl
Cl..
.
.
.
...
. .
. .
. . . .
. .
. .
VSEPR Model: AB3E
• PCl3
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
P ClCl
Cl..
.
.
.
...
. .
. .
. . . .
. .
. .
VSEPR Model: AB3E
Geometry: Trigonal Pyramidal
• CH2Cl2
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
• CH2Cl2
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
C ClCl
H..
.
.
. .
. . . .
. .
H
• CH2Cl2
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
C ClCl
H..
.
.
. .
. . . .
. .
HVSEPR Model: AB4
• CH2Cl2
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
C ClCl
H..
.
.
. .
. . . .
. .
HVSEPR Model: AB4
Geometry: Tetrahedral
• CO2
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
• CO2
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
C OO. . . .
. .. .
• CO2
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
C OO. . . .
. .. .
VSEPR Model: AB2
• CO2
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
C OO. . . .
. .. .
VSEPR Model: AB2
Geometry: Linear
• HCN
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
• HCN
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
C NH . .
• HCN
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
C NH . .
VSEPR Model: AB2
• HCN
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
C NH . .
VSEPR Model: AB2
Geometry: Linear
• Nitrite Ion
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
• NO2–
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
• NO2–
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
N OO. . . .
. .. .
. .
. .
• NO2–
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
VSEPR Model: AB2E
N OO. . . .
. .. .
. .
. .
• NO2–
Practice ProblemsDetermine the VSEPR model and geometry for each of the following molecules.
VSEPR Model: AB2E
Geometry: Bent
N OO. . . .
. .. .
. .
. .