Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.
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Transcript of Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.
![Page 1: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/1.jpg)
Molecular Geometry
Chapter 8 Part 2
Bucky ball
Carvone
![Page 2: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/2.jpg)
Molecular Geometry In this chapter we will discuss the geometries
of molecules in terms of their electronic structure.
– We will also explore two theories of chemical bonding: valence bond theory and molecular orbital theory.
– Molecular geometry is the general shape of a molecule, as determined by the relative positions of the atomic nuclei.
![Page 3: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/3.jpg)
The Valence-Shell Electron Pair Repulsion Model
The valence-shell electron pair repulsion (VSEPR) model predicts the shapes of molecules and ions by assuming that the valence shell electron pairs are arranged as far from one another as possible.
– To predict the relative positions of atoms around a given atom using the VSEPR model, you first note the arrangement of the electron pairs around that central atom.
![Page 4: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/4.jpg)
Predicting Molecular Geometry The following rules and figures will help
discern electron pair arrangements.
1. Draw the Lewis structure2. Determine how many electrons pairs are around the
central atom. Count a multiple bond as one pair.3. Arrange the electrons pairs
![Page 5: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/5.jpg)
Arrangement of Electron Pairs About an Atom
3 pairsTrigonal planar
2 pairsLinear
4 pairsTetrahedral
5 pairsTrigonal bipyramidal
6 pairsOctahedral
![Page 6: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/6.jpg)
Predicting Molecular Geometry The following rules and figures will help
discern electron pair arrangements.
![Page 7: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/7.jpg)
![Page 8: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/8.jpg)
![Page 9: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/9.jpg)
Predicting Molecular Geometry Two electron pairs (linear arrangement).
– You have two double bonds, or two electron groups about the carbon atom.
– Thus, according to the VSEPR model, the bonds are arranged linearly, and the molecular shape of carbon dioxide is linear. Bond angle is 180o.
C OO ::
::
![Page 10: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/10.jpg)
Predicting Molecular Geometry Three electron pairs (trigonal planar
arrangement).
– The three groups of electron pairs are arranged in a trigonal plane. Thus, the molecular shape of COCl2 is trigonal planar. Bond angle is 120o.
Cl
C
:
::
O
Cl :
::
: :
![Page 11: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/11.jpg)
Predicting Molecular Geometry Three electron pairs (trigonal planar
arrangement).
– Ozone has three electron groups about the central oxygen. One group is a lone pair.
– These groups have a trigonal planar arrangement.
O O
O:: :
::
:
![Page 12: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/12.jpg)
Predicting Molecular Geometry Three electron pairs (trigonal planar
arrangement).
– Since one of the groups is a lone pair, the molecular geometry is described as bent or angular.
O O
O:: :
::
:– Note that the electron pair arrangement includes the lone
pairs, but the molecular geometry refers to the spatial arrangement of just the atoms.
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Predicting Molecular Geometry Four electron pairs (tetrahedral
arrangement).
– Four electron pairs about the central atom lead to three different molecular geometries.
:Cl:
:::Cl:
:Cl
:: C Cl:
::
H
N
H
H :
:O
H
H :
![Page 14: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/14.jpg)
Predicting Molecular Geometry Four electron pairs (tetrahedral
arrangement).
![Page 15: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/15.jpg)
Predicting Molecular Geometry Five electron pairs (trigonal bipyramidal
arrangement).
– This structure results in both 90o and 120o bond angles.
: F :
::: F :
F :
::
: F
:: P
F :
::
![Page 16: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/16.jpg)
Predicting Molecular Geometry
Other molecular geometries are possible when one or more of the electron pairs is a lone pair.
SF4 ClF3 XeF2– Let’s try their Lewis structures.
![Page 17: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/17.jpg)
Predicting Molecular Geometry
Other molecular geometries are possible when one or more of the electron pairs is a lone pair.
S ClF3 XeF2
F
F
FF
see-saw
:
![Page 18: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/18.jpg)
Predicting Molecular Geometry
Other molecular geometries are possible when one or more of the electron pairs is a lone pair.
XeF2
see-saw
S
F
F
FF
: Cl
F
F
::
F
T-shape
![Page 19: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/19.jpg)
Predicting Molecular Geometry
Other molecular geometries are possible when one or more of the electron pairs is a lone pair.
see-saw
S
F
F
FF
: Cl
F
F
::
F
T-shape
Xe
F
F
::
:
linear
![Page 20: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/20.jpg)
Predicting Molecular Geometry Six electron pairs (octahedral
arrangement).
– This octahedral arrangement results in 90o bond angles.
F:
::
:F
::
SF:
::
:F
::
:F:
:
:F: :
![Page 21: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/21.jpg)
Predicting Molecular Geometry Six electron pairs (octahedral
arrangement).
– Six electron pairs also lead to other molecular geometries.
IF5 XeF4
![Page 22: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/22.jpg)
Predicting Molecular Geometry Six electron pairs (octahedral
arrangement).
XeF4I
FFF
:FF
square pyramid
![Page 23: Molecular Geometry Chapter 8 Part 2 Bucky ball Carvone.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649e035503460f94aedd2e/html5/thumbnails/23.jpg)
Predicting Molecular Geometry Six electron pairs (octahedral
arrangement).
I
FFF
:FF
square pyramid
XeF
F
:
FF
:
square planar