Chpt 9 - MO Theory. Localized e - model and hybrid orbitals sigma ( ) and pi ( ) bonds HW: Chpt 9 - pg. 430-437, #s 11, 12, 16, 29all, 32, 37, Due Mon Nov. 29. Covalent Bonding. Recall
What is shape and bond angles of CH4?
What is the valence electron configuration of a carbon atom?
We now want to think of the bonding orbitals for methane as being formed by an overlap of atomic orbitals.
Assume that the carbon atom has four equivalent atomic orbitals, arranged tetrahedrally.
Mixing of the native atomic orbitals to form special orbitals for bonding.
An s and 3 p orbitals become 4 equal sp3 orbitals
Draw the Lewis structure for C2H4 (ethylene)?
trigonal planar around each carbon atom
Above - sigma bonds in ethylene
Above - sigma bond & pi bond on carbon in ethylene
Left - total bonding in ethlene
Draw the Lewis structure for CO2.
Sigma () bond
Pi () bond
Yellow are 2 sp hybrid orbitals --> make bonds to O , Blue are unhybridized p orbitals that make bonds to O (double bonds)
Draw the Lewis structure for PCl5.
90o and 120o
Draw the Lewis structure for XeF4.
90o and 180o
Draw the Lewis structure for HCN.
Which hybrid orbitals are used?
Determine the bond angle and expected hybridization of the central atom for each of the following molecules:
NH3 SO2 KrF2
NH3 – 109.5o, sp3
SO2 – 120o, sp2
KrF2 – 90o, 120o, dsp3
CO2 – 180o, sp
ICl5 – 90o, 180o, d2sp3