Honors Shapes to Know: See Honors Packet
–
–
–
–
–
–
–
–
–
–
–
–
•
•
Linear
Trigonal Planar
Bent (with 3 e- regions and with 4)
Trigonal Pyramidal
Tetrahedral
Trigonal Bipyramidal
SeeSaw
T-Shaped
Linear
Octahedral
Square Pyramidal
Square Planar
VSEPR SHAPES FOR HONORS: http://youtu.be/FjjhUI4wFTE
Example of Shapes (honors): http://youtu.be/i3FCHVlSZc4
Honors
Honors
HONORS
HONORS
HONORS
Effect of Nonbonding Electrons
on Bond Angles
– Since electrons in a bond are attracted by two
nuclei, they do not repel as much as lone pairs.
– Bond angles decrease as the number of lone pairs
increase.
H
C
H
H
H
109.5O
N
H
H
H
O
107
O
H
H
104.5O
Exceptions to the Octet Rule (Honors)
• Less than Octet
– Ex:
BeH2
• Odd Number of Valence Electrons
– Ex:
NO
• More than Octet
– Ex:
SF6
Molecules with Expanded Valence
HONORS
Shells
• Trigonal
bipyramidal
electron
geometries:
Plane contains three
electrons pairs.
Fourth and fifth
electron pairs located
above and below this
plane.
HONORS
To minimize erepulsion, lone pairs
are always placed in
equatorial positions.
Molecules with Expanded Valence
Shells
HONORS
Octahedral
electron
geometries
Plane contains four
electron pairs.
Fifth and sixth
electron pairs located
above and below
plane.
Hybridization of Orbitals (Honors)
• To know hybridization type simply count # of egroups or “domains” around central atom
sp = 2 e- domains (linear e- geometry)
sp2 = 3 e- domains (trig. planar e- geometry)
sp3 = 4 e- domains (tetrahedral e- geometry)
sp3d = 5 e- domains (trig. bipyramidal e- geometry)
sp3d2 = 6 e- domains (octahedral e- geometry)
sp2
sp3
sp3d
Resonance
(Honors)
• Electrons “resonate” between multiple
bonding sites.
• Adds strength to all the bonds.
• Check if it is possible to draw double or triple
bonds at more than one bonding site.
Sigma and Pi Bonds (Honors)
• Sigma Bond:
– End to end overlap of orbitals
– All single bonds are sigma
– One of the bonds in a multiple
bond is a sigma
• Pi Bond:
– Side to side overlap of orbitals.
– Found in double or triple bonds.
HONORS
Bond Length and Bond Strength
• Longest = Single Bonds
• Shortest = Triple bonds
HONORS
Bond Strength
• Strongest (hardest to break)= triple bonds
• Weakest (easiest to break) = single bonds
Honors
Good for Review!!
• Crash Course Video: Molecular Geometries and
Electron Orbitals
• http://www.youtube.com/watch?v=cPDptc0wUYI
• Orbital Hybridization: (10 min)
http://www.youtube.com/watch?v=d1E18tBTlBg