Download VSEPR

Advanced Chemistry I
HYBRIDIZATION
VSEPR
-
VSEPR is useful for explaining _______________ of molecules.
-
Does not explain relationship between geometry and the _______________
occupied by bonding electrons.
Example:
Methane, CH4.
C
  _ _ __
1s
2s
2p
-
This shows that carbon has _______________ valence electrons.
-
The four electrons are of different energies… The 2p electrons are
_______________ in energy than the 2s electrons.
-
Methane is _______________ in shape, and each bond is _______________
in energy. How does carbon form 4 equal bonds if its pairs of electrons are of
different energies?
Hybridization
-
mixing of two or more atomic orbitals of _______________ energies on the
same atom to produce new orbitals of _______________ energies.
-
Used to explain how the orbitals of an atom become rearranged when the
atom forms covalent bonds.
Back to methane…
-
The 2s and 2p orbitals have different shapes.
-
To achieve four equal-energy bonds, carbon’s 2s and the three 2p orbitals
_______________ to form four new, _______________-energy orbitals called
_______________ orbitals.
C
  _ _ __
1s
-
2s
C
2p
 _ _ _ _
1s
109.5˚
____
The new _____ orbitals have _______________ energy than the 2s orbital and
_______________ energy than the 2p orbitals.
-
_______________ orbitals - orbitals of _______________ energy produced
by the _______________ of two or more orbitals on the same atom.
-
Ex:
o Methane
o Ammonia
o Water
The _______________ - _______________ geometry in BF3 is possible through the
hybridization of the s orbital and two p orbitals, yielding _____ hybridized orbitals.
B
  _ __ __
1s
2s
B
2p
 _ _ _ __
1s
____
120˚
2p
This hybridization also explains __________ geometry if a lone pair exists on the center
atom.
Ex: SiI2
Si
      _ _ __
1s
Si
2s
2p
3s
3p
~118˚
     _ _ _ __
1s
2s
2p
_____
3p
The _______________ geometry of beryllium fluoride (BeF2) is made by the
hybridization involving the s orbital and the one available empty p orbital to give us
_____ hybridized orbitals.
  __ __ __
Be
1s
2s
Be
2p
 _ _ __ __
1s
_____
180˚
2p
In summary…

The number of __________ __________ on the _______________ atom
determines the type of hybridization.
Hybridization
sp3
Bond Sites
Shape
Geometry
X
Tetrahedral
X
Trigonal pyramidal
4
Bent II
X
sp2
sp
3
2
X
Trigonal planar
X
Bent I
X
Linear