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Chapter 9 Chemical Bonding I: Basic Concepts
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2.
Which of these compounds is most likely to be ionic?
A.
B.
C.
D.
E.
4.
Which of these pairs of elements would be most likely to form an ionic compound?
A.
B.
C.
D.
E.
6.
Cl and I
Al and K
Cl and Mg
C and S
Al and Mg
Which of these compounds is most likely to be covalent?
A.
B.
C.
D.
E.
8.
GaAs
SrBr2
NO2
CBr4
H2O
KF
CaCl2
SF4
Al2O3
CaSO4
Complete this statement: Coulomb's law states that the magnitude of the force of interaction between two
charged bodies is
A.
B.
C.
D.
directly proportional to the product of the charges on the bodies and directly proportional to the
distance separating them.
directly proportional to the product of the charges on the bodies, and inversely proportional to the
square of the distance separating them.
inversely proportional to the charges on the bodies, and directly proportional to the square of the
distance separating them.
directly proportional to the sum of the charges on the bodies, and inversely proportional to the square
of the distance separating them.
10. The Lewis dot symbol for the S 2- ion is
A.
B.
C.
D.
E.
12. The Lewis dot symbol for the calcium ion is
A.
B.
C.
D.
E.
14. Which of these ionic solids would have the largest lattice energy?
A.
B.
C.
D.
E.
SrO
NaF
CaBr2
CsI
BaSO4
16. Which of these solids would have the highest melting point?
A.
B.
C.
D.
E.
NaI
NaF
MgO
MgCl2
KF
18. Calculate the energy change for the reaction
K(g) + Br(g)  K+(g) + Br- (g)
given the following ionization energy (IE) and electron affinity (EA) values
A.
B.
C.
D.
E.
-1,092 kJ/mol
-95 kJ/mol
95 kJ/mol
1,092 kJ/mol
1,187 kJ/mol
20. Use the Born-Haber cycle to calculate the lattice energy of LiCl(s) given the following data:
H(sublimation) Li = 155.2 kJ/mol
I1 (Li) = 520 kJ/mol
Bond energy (Cl-Cl) = 242.8 kJ/mol
EA (Cl) = 348 kJ/mol
Hf (LiCl(s)) = -408.8 kJ/mol
A.
B.
C.
D.
E.
-40 kJ/mol
40 kJ/mol
736 kJ/mol
857 kJ/mol
1,553 kJ/mol
22. Which of these elements has the greatest electronegativity?
A.
B.
C.
D.
E.
Na
As
Ga
Cs
Sb
24. Which of these elements has the greatest electronegativity?
A.
B.
C.
D.
E.
Se
Sb
K
Ga
Fe
26. Which of these elements has the greatest electronegativity?
A.
B.
C.
D.
E.
Mg
Ga
Si
Ba
Pb
28. What type of chemical bond holds the atoms together within a water molecule?
A.
B.
C.
D.
Ionic bond
Nonpolar covalent bond
Polar covalent bond
Coordinate covalent bond
30. Which of these bonds would have the greatest polarity (i.e., highest percent ionic character)?
A.
B.
C.
D.
E.
32. The covalent bond with the greatest polarity would form in which of these atom pairs?
A.
B.
C.
D.
E.
34. In which of these pairs of atoms would the bond have the greatest percent ionic character (i.e., most
polar)?
A.
B.
C.
D.
E.
36. Classify the
A.
B.
C.
bond in CH3OH as ionic, polar covalent, or nonpolar covalent.
ionic
polar covalent
nonpolar covalent
38. Classify the
A.
B.
C.
bond in CaCl2 as ionic, polar covalent, or nonpolar covalent.
ionic
polar covalent
nonpolar covalent
40. The number of lone electron pairs in the N2 molecule is ___.
A.
B.
C.
D.
E.
1
2
3
4
5
42. The total number of bonding electrons in a molecule of formaldehyde (H2CO) is
A.
B.
C.
D.
E.
3.
4.
6.
8.
18.
44. The Lewis structure for CS2 is:
A.
B.
C.
D.
46. Which of these Lewis structures is incorrect?
A.
B.
C.
D.
E.
48. The number of resonance structures for the sulfur dioxide molecule that satisfy the octet rule is
A.
B.
C.
D.
E.
1.
2.
3.
4.
none of these.
.
50. How many resonance structures are there for the cyclobutene molecule (C4H6; the four carbon atoms are
arranged in a ring)?
A.
B.
C.
D.
E.
1
2
3
4
none of these
52. How many covalent bonds will a nitrogen atom usually form?
A.
B.
C.
D.
E.
1
2
3
5
8
54. What is the formal charge on the oxygen atom in N2O (the atomic order is N-N-O)?
A.
B.
C.
D.
E.
0
+1
-1
-2
+2
56. The formal charge on the sulfur atom in the resonance structure of sulfur dioxide which has one single
bond and one double bond is
A.
B.
C.
D.
E.
0.
+1.
-1.
+2.
-2.
58. What is the formal charge on the singly bonded oxygens in the Lewis structure for the carbonate ion?
A.
B.
C.
D.
E.
-2
-1
0
+1
+2
60. Nitrous oxide, N2O, is sometimes called "laughing gas". What is the formal charge on the central nitrogen
atom in the best Lewis structure for nitrous oxide? (The atom connectivity is N-N-O.)
A. -2
B. -1
C. 0
D. +1
E. +2
62. In the Lewis structure of the iodate ion, IO3-, that satisfies the octet rule, the formal charge on the central
iodine atom is
A.
B.
C.
D.
E.
+2.
+1.
0.
-1.
-2.
64. For which of these species can you draw two resonance structures?
A.
B.
C.
D.
E.
CH2O
ClNO2
H2O
CH4
H2S
66. For which of these species is the best description of the bonding provided by two or more equivalent
resonance structures?
A.
B.
C.
D.
E.
HCO2SCNCNON3CO2
68. Which of these substances will display an incomplete octet in its Lewis structure?
A.
B.
C.
D.
E.
CO2
Cl2
ICl
NO
SO2
70. Which of these compounds does not follow the octet rule?
A.
B.
C.
D.
E.
NF3
CF4
PF5
AsH3
HCl
72. Which response includes all the molecules below that do not follow the octet rule?
(1) H2S
(2) BCl3
(3) PH3
(4) SF4
A.
B.
C.
D.
E.
(2) and (4)
(2) and (3)
(1) and (2)
(3) and (4)
(1) and (4)
74. Which of these molecules has an atom with an expanded octet?
A.
B.
C.
D.
E.
HCl
AsCl5
ICl
NCl3
Cl2
76. The structures of C2H4 and C2H5OH are
The enthalpy change due to the reaction of one mole of C2H4 with water to form C2H5OH can be estimated
by
A.
B.
C.
D.
E.
BE(C=C) - 2BE(C-C) - BE(C-O).
BE(C=C) + BE(O-H) - 2BE(C-C) - BE(C-O).
BE(C-O) + BE(C-C) - BE(O-H) - BE(C=C).
BE(O-H) + BE(C=C) - BE(C-H) - BE(C-O) - BE(C-C).
BE(C-H) + BE(C-O) + BE(C-C) - BE(O-H) - BE(C=C).
78. Estimate the enthalpy change for the combustion of one mole of acetylene, C2H2, to form carbon dioxide
and water vapor.
BE(C-H) = 456 kJ/mol
BE(CC) = 962 kJ/mol
BE(O=O) = 499 kJ/mol
BE(C=O) = 802 kJ/mol
BE(O-H) = 462 kJ/mol
A.
B.
C.
D.
E.
-1759 kJ/mol
+653 kJ/mol
+1010 kJ/mol
-1010 kJ/mol
-155 kJ/mol
80. Use bond energies to estimate the enthalpy change for the reaction of one mole of CH4 with chlorine gas to
give CH3Cl and hydrogen chloride.
BE(C-H) = 414 kJ/mol
BE(C-Cl) = 326 kJ/mol
BE(H-Cl) = 432 kJ/mol
BE(Cl-Cl) = 243 kJ/mol
A.
B.
C.
D.
E.
-101 kJ/mol
-106 kJ/mol
+331 kJ/mol
+106 kJ/mol
+101 kJ/mol
82. Use the bond enthalpy data given to estimate the heat released when 50.0 g of propane gas, C3H8, burns in
excess oxygen to yield carbon dioxide and water vapor at 25C.
BE(C-C) = 347 kJ/mol
BE(C=O in CO2) = 799 kJ/mol
BE(C-H) = 414 kJ/mol
BE(O-H) = 460 kJ/mol
BE(O=O) = 498.7 kJ/mol
A.
B.
C.
D.
E.
1360 kJ
2240 kJ
2370 kJ
1540 kJ
1970 kJ
84. The standard enthalpy of formation of ammonia at 25C is -46.3 kJ/mol. Estimate the N-H bond enthalpy
at this temperature.
(Given: BE(NN)=941.4 kJ/mol, BE(H-H) = 436.4 kJ/mol)
A.
B.
C.
D.
E.
383 kJ/mol
475 kJ/mol
360 kJ/mol
391 kJ/mol
459 kJ/mol
Chapter 9 Chemical Bonding I: Basic Concepts Key
2.B
4.C
6.C
8.B
10.B
12.D
14.A
16.C
18.C
20.D
22.B
24.A
26.C
28.C
30.D
32.E
34.D
36.B
38.A
40.B
42.D
44.C
46.E
48.B
50.D
52.C
54.C
56.B
58.B
60.D
62.A
64.B
66.A
68.D
70.C
72.A
74.B
76.D
78.D
80.A
82.B
84.D