Name: 
 

Bonding & Molecular Structure


Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 
For an atom of a main group element, the number of valence electrons is equal to
a.
its number of core electrons.
b.
the principle quantum number of its outer shell.
c.
its period number.
d.
its group number.
e.
eight minus its group number.
 

 2. 
What is the expected number of valence electrons for an atom of a group 6A element?
a.
0
b.
1
c.
2
d.
4
e.
6
 

 3. 
A silicon atom has ____ valence electrons.
a.
0
b.
2
c.
4
d.
6
e.
10
 

 4. 
Which of the following compounds is expected to have the strongest ionic bonds?
a.
MgO
b.
KBr
c.
NaI
d.
SrO
e.
CaS
 

 5. 
What is the total number of valence electrons in a carbonate ion?
a.
20
b.
22
c.
24
d.
26
e.
30
 

 6. 
Which of the following species will have a Lewis structure most like that of carbon disulfide, CS2?
a.
NO2-
b.
SO2
c.
H2S
d.
SF2
e.
SCN-
 

 7. 
How many lone-pair electrons surround each nitrogen atom in hydrazine, N2H4?
a.
0
b.
1/2
c.
1
d.
3
e.
4
 

 8. 
Which of the following is a correct Lewis structure for ozone, O3?

bondingmolecstructu_files/i0090000.jpg
a.
1
b.
2
c.
3
d.
4
e.
5
 

 9. 
Which of the following are resonance structures for sulfur dioxide, SO2?

bondingmolecstructu_files/i0100000.jpg
a.
1 and 2
b.
2 and 4
c.
3 and 4
d.
1, 2, and 3
e.
2, 3, and 4
 

 10. 
When both of the electrons in a molecular bond originate from the same atom, the bond is called a(n)
a.
double bond.
b.
coordinate covalent bond.
c.
pi bond.
d.
sigma bond.
e.
ionic bond.
 

 11. 
Which of the following species will have a Lewis structure most like that of SF4?
a.
XeF4
b.
SO42-
c.
ICl4+
d.
PF4+
e.
IO4-
 

 12. 
Use VSEPR theory to predict the molecular geometry of H3O+.
a.
trigonal-pyramidal
b.
trigonal-planar
c.
bent
d.
T-shaped
e.
linear
 

 13. 
Use VSEPR theory to predict the molecular geometry of CS2.
a.
linear
b.
bent
c.
trigonal-planar
d.
tetrahedral
e.
octahedral
 

 14. 
Use VSEPR theory to predict the molecular geometry of CO32-.
a.
bent
b.
tetrahedral
c.
trigonal-pyramidal
d.
T-shaped
e.
trigonal-planar
 

 15. 
Predict which of the following compounds will have the most polar covalent bond(s).
a.
HF
b.
CBr4
c.
H2S
d.
NCl3
e.
HI
 

 16. 
In molecules, as bond order increases,
a.
both bond length and bond energy increase.
b.
both bond length and bond energy decrease.
c.
bond length increases and bond energy is unchanged.
d.
bond length is unchanged and bond energy increases.
e.
bond length decreases and bond energy increases.
 

 17. 
Use Lewis structures to predict the bond order for a nitrogen-oxygen bond in the nitrite ion, NO2-.
a.
1/2
b.
1
c.
4/3
d.
3/2
e.
3
 

 18. 
The standard molar enthalpy of formation of ClF3 is -405 kJ.

1/2 Cl2(g) + 3/2 F2(g) ® ClF3(g)

The bond energies of Cl2 and F2 are 242 kJ and 155 kJ/mol, respectively. Calculate the energy of an Cl-F bond.
a.
8 kJ/mol
b.
87 kJ/mol
c.
207 kJ/mol
d.
253 kJ/mol
e.
802 kJ/mol
 

 19. 
When heated, azomethane decomposes into nitrogen gas and ethane gas.

CH3N=NCH3(g) ® N2(g) + C2H6(g)

Bond
Bond Energy (kJ/mol)
Bond
Bond Energy (kJ/mol)
C-H
413
N-N
163
C-N
305
N=N
418
C-C
346
Nbondingmolecstructu_files/i0200000.jpgN
945

Using average bond energies, calculate the enthalpy of reaction.
a.
-611 kJ
b.
-527 kJ
c.
-429 kJ
d.
-313 kJ
e.
-263 kJ
 

 20. 
What is the molecular geometry of SiH4?
a.
bent
b.
linear
c.
tetrahedral
d.
trigonal pyramidal
e.
There is not enough information
 

 21. 
What is the molecular geometry of PH3?
a.
bent
b.
linear
c.
tetrahedral
d.
trigonal pyramidal
e.
There is not enough information
 

 22. 
Which molecule listed below has a polar covalent bond?
a.
NaCl
b.
H2O
c.
H2
d.
All of the above
e.
None of the above
 

 23. 
Which among the following molecules is/are nonpolar?
a.
CCl4
b.
CO2
c.
BH3
d.
All of the above
e.
None of the above
 

 24. 
Which among the following compounds will dissolve in water?
a.
NaCl
b.
SiO2
c.
CCl4
d.
All of the above
e.
None of the above
 

 25. 
Which of the following statements is TRUE for the covalent molecule HCl?
a.
Chlorine is more electronegative and the shared electron pair is likely to be found on the hydrogen atom.
b.
Chlorine is more electronegative and the shared electron pair is likely to be found on the chlorine atom.
c.
Hydrogen is more electronegative and the shared electron pair is likely to be found on the hydrogen atom.
d.
Hydrogen is more electronegative and the shared electron pair is likely to be found on the chlorine atom.
e.
None of the above.
 



 
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