CHE 1401 - Summer 2015 - Chapter 8
Homework 8 (Chapter 8: Basic concepts of chemical bonding)
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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the
question.
1) Which of the following has the bonds correctly arranged in order of increasing
polarity?
A) OF, NF, BeF, MgF
B) OF, BeF, MgF, NF
C) MgF, BeF, NF, OF
D) BeF, MgF, NF, OF
E) NF, BeF, MgF, OF
1)
2) Of the atoms below, __________ is the most electronegative.
A) Br
B) F
C) Cl
D) N
2)
E) O
3) For resonance forms of a molecule or ion, __________.
A) the same atoms need not be bonded to each other in all resonance forms
B) one always corresponds to the observed structure
C) all the resonance structures are observed in various proportions
D) there cannot be more than two resonance structures for a given species
E) the observed structure is an average of the resonance forms
3)
4) In the Lewis symbol for a sulfur atom, there are __________ paired and
__________ unpaired electrons.
A) 0, 6
B) 5, 1
C) 2, 2
D) 2, 4
E) 4, 2
4)
5) As the number of covalent bonds between two atoms increases, the distance
between the atoms __________ and the strength of the bond between them
__________.
A) increases, increases
B) decreases, decreases
C) increases, decreases
D) decreases, increases
E) is unpredictable
5)
6) Which of the following does not have eight valence electrons?
A) Rb+1
B) Xe
C) ClD) Ti+4
6)
1
E) Sr+1
7) The chloride of which of the following metals should have the greatest lattice
energy?
A) rubidium
B) lithium
C) cesium
D) potassium
E) sodium
7)
8) Which two bonds are most similar in polarity?
A) BF and ClF
B) IBr and SiCl
C) ClCl and BeCl
D) AlCl and IBr
E) OF and ClF
8)
9) Which of the following names is/are correct for the compound SnCl4?
A) tin (II) chloride and tin (IV) chloride
B) tin chloride and tin (II) tetrachloride
C) tin chloride
D) tin (IV) tetrachloride
E) tin tetrachloride and tin (IV) chloride
9)
For the questions that follow, consider the BEST Lewis structures of the following oxyanions:
(i) NO2- (ii) NO3- (iii) SO32- (iv)SO42- (v) BrO310) There can be four equivalent best resonance structures of __________.
A) (i)
B) (ii)
C) (iii)
D) (iv)
E) (v)
10)
11) In which of the ions do all X-O bonds (X indicates the central atom) have the
same length?
A) none
B) all
C) (i) and (ii)
D) (iii) and (v)
E) (iii), (iv), and (v)
11)
12) The central atom in __________ does not violate the octet rule.
A) SF4
B) CF4
C) ICl4D) KrF2
12)
2
E) XeF4
13) A valid Lewis structure of __________ cannot be drawn without violating the
octet rule.
A) SO3
B) ClF3
C) CO2
D) CCl4
E) PCl3
13)
14) In ionic bond formation, the lattice energy of ions ________ as the magnitude of
the ion charges _______ and the radii __________.
A) increases, decrease, increase
B) decreases, increase, increase
C) increases, increase, increase
D) increases, decrease, decrease
E) increases, increase, decrease
14)
15) A valid Lewis structure of __________ cannot be drawn without violating the
octet rule.
A) SO32B) NF3
C) SO2
D) CF4
E) BeH2
15)
16) Using the Born-Haber cycle, the ΔHf° of KBr is equal to __________.
A) ΔHf°[K (g)] + ΔHf°[Br (g)] + I1(K) + E(Br) - ΔHlattice
B) ΔHf°[K (g)] + ΔHf°[Br (g)] + I1(K) + E(Br) + ΔHlattice
C) ΔHf°[K (g)] - ΔHf°[Br (g)] + I1(K) - E(Br) + ΔHlattice
16)
D) ΔHf°[K (g)] - ΔHf°[Br (g)] - I1(K) - E(Br) - ΔHlattice
E) ΔHf°[K (g)] + ΔHf°[Br (g)] - I1 - E(Br) + ΔHlattice
17) Which atom can accommodate an octet of electrons, but doesn't necessarily
have to accommodate an octet?
A) H
B) C
C) O
D) N
E) B
17)
18) Of the bonds below, __________ is the least polar.
A) C, F
B) Na, Cl
C) Na, S
D) P, S
18)
E) Si, Cl
19) Most explosives are compounds that decompose rapidly to produce __________
products and a great deal of __________.
A) liquid, heat
B) gaseous, heat
C) gaseous, gases
D) soluble, heat
E) solid, gas
19)
20) Of the atoms below, __________ is the least electronegative.
A) Ca
B) Rb
C) Si
D) F
20)
3
E) Cl
21) The type of compound that is most likely to contain a covalent bond is
__________.
A) a solid metal
B) one that is composed of a metal from the far left of the periodic table and a
nonmetal from the far right of the periodic table
C) one that is composed of only nonmetals
D) held together by the electrostatic forces between oppositely charged ions
E) There is no general rule to predict covalency in bonds.
21)
22) The Lewis structure of the CO32- ion is __________.
A)
22)
B)
C)
D)
4
E)
23) The electron configuration [Kr]4d10 represents __________.
A) Sn+2
B) Ag+1
C) Sr+2
D) Rb+1
23)
E) Te+2
24) A valid Lewis structure of __________ cannot be drawn without violating the
octet rule.
A) NI3
B) SiF4
C) SO2
D) CO2
E) ICl5
24)
25) In the nitrite ion (NO2-), __________.
25)
A) one bond is a double bond and the other is a single bond
B) both bonds are double bonds
C) there are 20 valence electrons
D) both bonds are single bonds
E) both bonds are the same
26) Which of the following has eight valence electrons?
A) Ti4+
26)
B) ClC) Kr
D) Na+
E) all of the above
27) The oxidation number of phosphorus in PF3 is __________.
A) +2
B) +1
C) -2
D) -3
28) The Lewis structure of N2H2 shows __________.
A) each nitrogen has two nonbonding electron pairs
B) a nitrogen-nitrogen single bond
C) each hydrogen has one nonbonding electron pair
D) a nitrogen-nitrogen triple bond
E) each nitrogen has one nonbonding electron pair
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27)
E) +3
28)
29) Bond enthalpy is __________.
A) always negative
B) always zero
C) sometimes positive, sometimes negative
D) always positive
E) unpredictable
29)
30) Which of the following names is/are correct for the compound TiO2?
A) titanium oxide
B) titanium (IV) dioxide
C) titanium dioxide and titanium (IV) oxide
D) titanium (II) oxide
E) titanium oxide and titanium (IV) dioxide
30)
31) Of the molecules below, the bond in __________ is the most polar.
A) HBr
B) HCl
C) H2
D) HI
31)
E) HF
32) Given that the average bond energies for C-H and C-Br bonds are 413 and 276
kJ/mol, respectively, the heat of atomization of bromoform (CHBr3) is
__________ kJ/mol.
A) -1378
B) 1378
C) 689
D) -689
E) 1241
32)
33) Of the ions below, only __________ has a noble gas electron configuration.
A) KB) S3C) ClD) O 2+
E) I+
33)
34) Of the following, __________ cannot accommodate more than an octet of
electrons.
A) As
B) P
C) I
D) S
E) O
34)
35) Dynamite consists of nitroglycerine mixed with __________.
A) potassium nitrate
B) damp KOH
C) diatomaceous earth or cellulose
D) solid carbon
E) TNT
35)
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36) Why don't we draw double bonds between the Be atom and the Cl atoms
in BeCl2?
A) That would result in the formal charges not adding up to zero.
B) That would result in more than eight electrons around beryllium.
C) That would give positive formal charges to the chlorine atoms and a
negative formal charge to the beryllium atom.
D) That would result in more than eight electrons around each chlorine atom.
E) There aren't enough electrons.
36)
37) A valid Lewis structure of __________ cannot be drawn without violating the
octet rule.
A) CF4
B) NF3
C) PO43D) SeF4
E) SiF4
37)
38) Of the possible bonds between carbon atoms (single, double, and triple),
__________.
A) a double bond is stronger than a triple bond
B) a triple bond is longer than a single bond
C) a double bond is longer than a triple bond
D) a single bond is stronger than a double bond
E) a single bond is stronger than a triple bond
38)
39) Based on the octet rule, boron will most likely form a __________ ion.
A) B2+
B) B3+
C) B3D) B1+
E) B2-
39)
40) Resonance structures differ by __________.
A) number of atoms only
B) number of electrons only
C) placement of electrons only
D) placement of atoms only
E) number and placement of electrons
40)
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