19) Choose the compound below that should have the highest melting point according to the ionic
bonding model.
A) SrI2
B) MgF2
C) CaCl2
D) SrF2
E) SrBr2
20) Choose the compound below that should have the lowest melting point according to the ionic
bonding model.
A) LiF
B) LiCl
C) CsI
D) KBr
E) RbI
21) Identify the number of bonding pairs and lone pairs of electrons in N2.
A) 6 bonding pair and 1 lone pair
B) 4 bonding pair and 2 lone pairs
C) 3 bonding pairs and 2 lone pairs
D) 2 bonding pairs and 1 lone pair
E) 2 bonding pairs and 3 lone pairs
22) Of the following elements, which has the highest electronegativity?
A) Si
B) P
C) Ti
D) Ge
23) Of the following elements, which has the lowest electronegativity?
A) Sr
B) I
C) Ba
D) At
24) Place the following elements in order of increasing electronegativity.
Na Rb P
A) P < Na < Rb
B) Na < P < Rb
C) Rb < P < Na
D) Rb < Na < P
E) P < Rb < Na
25) Place the following elements in order of decreasing electronegativity.
S F Se
A) Se > S > F
B) F > Se > S
C) Se > F > S
D) S > F > Se
E) F > S > Se
26) Place the following elements in order of increasing electronegativity.
Ba Se Li
A) Ba < Li < Se
B) Li < Se < Ba
C) Ba < Se < Li
D) Se < Ba < Li
E) Se < Li < Ba
27) List the following compounds in decreasing electronegativity difference.
F2 HF KF
A) KF > F2 > HF
B) F2 > HF > KF
C) HF > KF > F2
D) KF > HF > F2
28) Choose the bond below that is most polar.
A) C-N
B) C-F
C) N-O
D) C-C
E) Cl-Cl
29) Using periodic trends, place the following bonds in order of increasing ionic character.
S-Cl Se–Cl O-Cl
A) Se-Cl < S-Cl < O-Cl
B) S-Cl < Se-Cl < O-Cl
C) O-Cl < Se-Cl < S-Cl
D) Se-Cl < O-Cl < S-Cl
E) O-Cl < S-Cl < Se-Cl
30) Using periodic trends, place the following bonds in order of decreasing ionic character.
Sb-F P-F As-F
A) Sb-F > As-F > P-F
B) As-F > Sb-F > P-F
C) Sb-F > P-F > As-F
D) P-F > As-F > Sb-F
E) Sb-F > P-F > As-F
31) Which molecule or compound below contains a pure covalent bond?
A) Li2CO3
B) SCl6
C) Br2
D) PCl3
E) NaCl
32) Which molecule or compound below contains a polar covalent bond?
A) C2H4
B) ZnS
C) LiI
D) NCl3
E) AgI
33) Which molecule or compound below contains an ionic bond?
A) CO2
B) C2Br4
C) SiF4
D) OCl2
E) NH4NO3
34) The electronegativity is 2.1 for H and 1.9 for Pb. Based on these electronegativities PbH4 would be
expected to
A) be ionic and contain H– ions.
B) be ionic and contain H+ ions.
C) have polar covalent bonds with a partial negative charges on the H atoms.
D) have polar covalent bonds with a partial positive charges on the H atoms.
35) The compound ClF contains
A) ionic bonds.
B) nonpolar covalent bonds.
C) polar covalent bonds with partial negative charges on the F atoms.
D) polar covalent bonds with partial negative charges on the Cl atoms.
36) The phosphorus atom in PCl3 would be expected to have a
A) partial positive (δ+) charge.
B) partial negative (δ-) charge.
C) 3+ charge.
D) 3- charge.
37) The iodine atom in I2 would be expected to have a
A) charge of 1-.
B) partial charge δ-.
C) partial charge δ+.
D) charge of 0.
38) Give the number of valence electrons for SBr4.
A) 28
B) 30
C) 32
D) 34
39) Give the number of pairs of valence electrons for BF3.
A) 16
B) 8
C) 14
D) 10
E) 12
40) In the best Lewis structure for NO +, what is the formal charge on the N atom?
A) -1
B) 0
C) +1
D) +2
41) Which of the following elements can form compounds with an expanded octet?
A) Se
B) C
C) Li
D) F
E) All of the above elements can form compounds with an expanded octet.
42) Which of the following elements can form compounds with an expanded octet?
A) O
B) Br
C) F
D) Be
E) None of the above can form compounds with an expanded octet.
43) How many of the following elements can form compounds with an expanded octet?
I O Br Xe
A) 2
B) 0
C) 3
D) 1
E) 4
44) How many of the following elements can form compounds with an expanded octet?
P Kr Xe B
A) 0
B) 1
C) 2
D) 3
E) 4
45) How many lone pairs of electrons are on the As atom in AsCl3?
A) 0
B) 1
C) 2
D) 3
46) Which element can expand its valence shell to accommodate more than eight electrons?
A) N
B) O
C) Br
D) He
47) Which of the following contains an atom that does not obey the octet rule?
A) CsI
B) SnO2
C) ClF5
D) ClF
48) How many lone pairs of electrons are on the S atom in SF4 ?
A) 0
B) 1
C) 2
D) 3
49) How many lone pairs are on the Br atom in BrCl2–?
A) 0
B) 1
C) 2
D) 3
50) Choose the bond below that is the strongest.
A) C-F
B) C=O
C) C-I
D) I-I
E) C≡N
51) Choose the bond below that is the strongest.
A) N=O
B) N-F
C) C-O
D) N-C
E) N=N
52) Choose the bond below that is the weakest.
A) Na-Br
B) Br-Br
C) C=N
D) Li-I
E) C=N
53) Choose the bond below that is the weakest.
A) C≡O
B) N≡N
C) C-I
D) C=O
E) K-Br
Matching Questions
Match the following.
A) metallic bond
B) weakest ionic bond
C) strongest covalent bond
D) highest melting point
E) longest covalent bond
1) Sr-Sr
Diff: 1 Page Ref: 9.2
2) Cs-I
Diff: 1 Page Ref: 9.4
3) Ca-O
Diff: 1 Page Ref: 9.4
4) Se-I
Diff: 1 Page Ref: 9.5
5) C=N
Diff: 1 Page Ref: 9.5
40
Short Answer Questions
1) Describe a covalent bond.
2) Draw the Lewis Dot structure for Al3+.
3) Explain why the lattice energy of MgS is approximately 4 times as large as that of NaCl.
4) List the most electronegative atom.
5) List the least electronegative atom.
6) Define dipole moment.
7) How are electron affinity and electronegativity different?
8) Describe the difference between a pure covalent bond and a polar covalent bond.
9) Draw the Lewis structure for the acetate ion, CH3CO2⁻, including any important resonance
structures. Label each atom with its formal charge.
10) Draw the Lewis structure for BrO3–. Make sure to include any important resonance structures.
11) Define formal charge.
12) Define bond energy.