CHAPTER 10- Chemical bondings II:
Molecular Geometry and Hybridization of Atomic Orbitals
1. Using VSEPR model, predict the molecular geometry (molecular shape) and electron
geometry of the followings:
O3
CO32ICl2NF3
SnCl32. Predict the approximate value for the bond angles for each carbon indicated in the
following compounds:
H
H
(a) H - C - C  C -H
(b) H - C - O -H
H
H
3. Predict whether the following molecules are polar or nonpolar;
H
Cl
Cl
Cl
SO2
C=C
C=C
Cl
H
H
H
NF3
CS2
4. Indicate the hybridization of orbitals by the central atom in each of the following;
SO32-
NH4+
SO3
SCl2
5. Consider the following molecules , answer the following questions for only marked
(*)carbons.
*
(a) O = C
I)
Cl
Cl
H H
(b) H - C* - C* = C - C*  N
H
H
predict the bond angles
II) give hybridizations
III) determine the total number of sigma () and pi () electrons in the molecules.
VI) predict the molecular geometry ( molecular shape) and electron geometry around
each marked carbon.
6. Draw Lewis dot structures for following molecules and ions, predict which will exhibits
delocalized pi () bonding ( resonance structure).
SO32NH4+
NO2
7. Consider the following molecules and ions:
NCS1
OCN-
I3-
He2-
C22-
O22+
CN-
N2-
a) write molecular orbital electron configuration
b) predict the bond order
c) predict the stability (stable or unstable)
8. Consider CH3 , CH3+ , and CH3-, for each:
a) draw Lewis dot structure
b) predict electron geometry and molecular geometry
c) using hybrid orbitals , describe the bonding ( orbital hybridization)
d) predict the bond angles
e) predict the polarity ( polar or non-polar)
9. Consider H2 , H2+ , H2- ; for each,
a) draw energy-level diagram.
b) determine total number of electrons.
c) write Lewis dot structure.
d) calculate the bond order.
e) determine the magnetic properties(in terms of paramagnetic or diamagnetic).
f) Compare the stability and arrange the in order of increasing stability.
10. Identify the following molecules or ions as stable or unstable. Explain why? Compare the
stability.
He2
He2+
O2
O2O22CHAPTER 10- Chemical bondings II: (Answers)
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Molecular Geometry and Hybridization of Atomic Orbitals
1. Using VSEPR model, predict the molecular geometry (molecular shape) and electron geometry
of the followings:
O3
=>MG = bent; EG = trigonal planar
CO32- => MG = trigonal planar;
EG same
ICl2 => MG = linear;
EG = trigonal bipyramidal
NF3 => MG = trigonal pyramidal;
EG = tetrahedral
SnCl3 => MG = trigonal pyramidal;
EG = tetrahedral
2. Predict the approximate value for the bond angles for each carbon indicated in the
following compounds:
H
H
(a) H - C - C  C -H
(b) H - C - O -H
H
H
109.5º, 180º, 180º
109.5º
3. Predict whether the following molecules are polar or nonpolar;
H
Cl
Cl
Cl
SO2 P NF3 P CS2 NP
C=C
C=C
Cl
H
H
H
NP
P
4. Indicate the hybridization of orbitals by the central atom in each of the following;
SO32- sp3
SO3 sp2
NH4+ sp3
SCl2 sp3
5. Consider the following molecules , answer the following questions for only marked
(*)carbons.
Cl
H H
*
(a) O = C
(b) H - C* - C* = C - C*  N
Cl
H
H
I) predict the bond angles
II) give hybridizations
120, 109.5, 120, 120, 180
sp2, sp3, sp2, sp2, sp
III) determine the total number of sigma () and pi () electrons in the molecules.
(a) 6  , 2 
(b) 18 , 6 
VI) predict the molecular geometry ( molecular shape) and electron geometry around each
marked carbon.
(a) MG = trigonal planar, EG = same
(b) Carbons 1,2,3,4 respectively:
MG = tetrahedral, trigonal planar, trigonal planar, linear. EG = same
6. Draw Lewis dot structures for following molecules and ions, predict which will exhibits
delocalized pi () bonding ( resonance structure).
3
SO32- No
NH4+
No
NO2
Yes
NCS-
Yes
OCN- Yes
I3- No
7. Consider the following molecules and ions:
a) write molecular orbital electron configuration
b) predict the bond order
c) predict the stability (stable or unstable)
He2- Does not apply
C22- σ21sσ*21sσ22sσ*22sπ22pxπ22pyσ22pz , B.O = 3, stable
O22+ σ21sσ*21sσ22sσ*22sσ22pzπ22pxπ22py , B.O =3, stable
CN- σ21sσ*21sσ22sσ*22sπ22pxπ22pyσ22pz , B.O. =3, stable
N2- σ21sσ*21sσ22sσ*22sπ22pxπ22pyσ22pzπ*12px , B.O. = 2.5, stable
8. Consider CH3 , CH3+ , and CH3-, for each:
a) draw Lewis dot structure
b) predict electron geometry and molecular geometry
c) using hybrid orbitals , describe the bonding ( orbital hybridization)
d) predict the bond angles
e) predict the polarity ( polar or non-polar)
9. Consider for each
H2
H2+
H2a) draw energy-level diagram.
b) determine total number of electrons.
c) write Lewis dot structure.
d) calculate the bond order.
e) determine the magnetic properties(in terms of paramagnetic or diamagnetic).
f) Compare the stability and arrange the in order of increasing stability.
10. Identify the following molecules or ions as stable or unstable. Explain why? Compare the
stability.
He2 unstable, bond order is zero.
He2+ stable, bond order is 0.5
O2 stable, bond order is 2
O2- stable, bond order is 1.5
O22- stable, bond order is 1
Order of increasing stability:
He2 < He2+ < O22- < O2- < O2
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