Multiple-Choice - Write you final answers on a separate piece of paper with your name.
1.
There are __________ paired and __________ unpaired electrons in the Lewis symbol for a phosphorus
atom.
4, 2
2, 4
2, 3
4, 3
0, 3
2.
Based on the octet rule, magnesium most likely forms a __________ ion.
Mg 2+
Mg 2Mg6Mg6+
Mg-
3.
There are __________ unpaired electrons in the Lewis symbol for an oxygen atom.
0
1
2
4
3
4.
How many unpaired electrons are there in the Lewis structures of a N3- ion?
0
1
2
3
This cannot be predicted.
5.
The noble gas configuration of the phosphide ion (P3- ) is __________.
[Ne]3s2
[Ne]3s2 3p1
[Ne]3s2 3p3
[Ne]3p2
[Ne]3s2 3p6
6.
The halogens, alkali metals, and alkaline earth metals have __________ valence electrons, respectively.
7, 4, and 6
1, 5, and 7
8, 2, and 3
7, 1, and 2
2, 7, and 4
7.
Which of the following would have to gain two electrons in order to achieve a noble gas electron
configuration __________?
O
Sr
Na
Se
Br
Br
8.
Sr
O, Se
Sr, O, Se
[Ne]3s2 3p6
[Kr]3s2 2p-6
The electron configuration of the S2- ion is __________.
[Ar]3s2 3p6
9.
Na
[Ar]3s2 3p2
[Ne]3s2 3p2
The principal quantum number of the electrons that are lost when tungsten forms a cation is __________.
6
5
4
3
2
10. Which one of the following species has the electron configuration [Ar]3d4 ?
Cr 2+
Mn 2+
V3+
Fe3+
K+
[Ar]4s2 3d9
[Ne]3s2 3p10
11. What is the electron configuration for the Co 2+ ion?
[Ar]4s1 3d6
[Ar]4s0 3d7
[Ar]4s0 3d5
12. How many single covalent bonds must a silicon atom form to have a complete octet in its valence shell?
a. 3
4
1
2
0
13. What is the maximum number of double bonds that a carbon atom can form?
a. 4
1
0
2
3
14. Given the electronegativities below, which covalent single bond is most polar?
Element:
Electronegativity:
C–H
H
2.1
C
2.5
N
3.0
N–H
O
3.5
O–H
1
O–C
O–N
15. Electronegativity __________ from left to right within a period and __________ from top to bottom
within a group.
a. decreases, increases
b. increases, increases
c. increases, decreases
d. stays the same, increases
e. increases, stays the same
16. A nonpolar bond will form between two __________ atoms of __________ electronegativity.
a. different, opposite
b. identical, different
c. different, different
d. similar, different
e. identical, equal
17. The Lewis structure of AsH3 shows __________ nonbonding electron pair(s) on As.
a. 0
b. 1
c. 2
d. 3
e. This cannot be determined from the data given.
18. The Lewis structure of PF3 shows that the central phosphorus atom has __________ nonbonding and
__________ bonding electron pairs.
a. 2, 2
1, 3
3, 1
1, 2
3, 3
19. The Lewis structure of HCN (H bonded to C) shows that __________ has __________ nonbonding
electron pairs.
a. C, 1
N, 1
H, 1
N, 2
C, 2
20. The formal charge on nitrogen in NO3 - is __________.
a.
-1
0
+1
+2
–2
21. The formal charge on sulfur in SO42- is __________, where the Lewis structure of the ion is:
a.
-2
0
+2
+4
-4
22. In the Lewis structure of ClF, the formal charge on Cl is __________ and the formal charge on F is
__________.
a. -1, -1
0, 0
0, -1
+1, -1
-1, +1
2
23. In the resonance form of ozone shown below, the formal charge on the central oxygen atom is __________.
0
+1
-1
+2
-2
24. Using the table of average bond energies below, the ΔH for the reaction is __________ kJ.
Bond:
D (kJ/mol):
C≡C
839
C–C
348
+160
H–I
299
C–I
240
-160
C–H
413
-217
-63
+63
25. Using the table of average bond energies below, the △H for the reaction is __________ kJ.
Bond: C–O
C=O
C≡O
C–H
H–H
C  O (g) + 2H2 (g)  H3C-O-H (g)
D (kJ/mol): 358
799
1072
413
436
+276
-276
+735
-735
O–H
463
-116
26. Using the table of bond dissociation energies, the ΔH for the following gas-phase reaction is ________ kJ.
A) 291
B) 2017
C) -57
D) -356
E) -291
27. Which of the following does not have eight valence electrons?
A) Ca +
B) Rb +
C) Xe
D) Br E) All of the above have eight valence electrons.
28. In which of the molecules below is the carbon-carbon distance the shortest?
A) H2C=CH2
B) H-C  C-H C) H3C-CH3
D) H2 C=C=CH2
E) H3C-CH2 -CH3
29. Of the atoms below, __________ is the most electronegative.
A) Si B) Cl C) Rb D) Ca E) S
30. Of the atoms below, __________ is the least electronegative.
A) Rb B) F
C) Si
D) Cl E) Ca
31. Of the bonds below, __________ is the least polar.
A) Na, S
B) P, S
C) C, F
D) Si, Cl
E) Na, Cl
32. Which of the following has the bonds correctly arranged in order of increasing polarity?
A) Be–F, Mg–F, N–F, O–F
B) O–F, N–F, Be–F, Mg–F
C) O–F, Be–F, Mg–F, N–F
D) N–F, Be–F, Mg–F, O–F
E) Mg–F, Be–F, N–F, O–F
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33. The Lewis structure of N 2 H 2 shows __________.
A) a nitrogen-nitrogen triple bond
B) a nitrogen-nitrogen single bond
C) each nitrogen has one nonbonding electron pair D) each nitrogen has two nonbonding electron pairs
E) each hydrogen has one nonbonding electron pair
34. The Lewis structure of the CO32- ion is __________.
A)
B)
C)
D)
E)
35. For resonance forms of a molecule or ion, __________.
A) one always corresponds to the observed structure
B) all the resonance structures are observed in various proportions
C) the observed structure is an average of the resonance forms
D) the same atoms need not be bonded to each other in all resonance forms
E) there cannot be more than two resonance structures for a given species
36. Of the following, __________ cannot accommodate more than an octet of electrons.
A) P
B) As
C) O
D) S
E) I
37. Which atom can accommodate an octet of electrons, but doesn't necessarily have to accommodate an octet?
A) N
B) C
C) H
D) O
E) B
38. Of the bonds C–N, C=N, and C≡N, the C–N bond is __________.
A) strongest/shortest
B) strongest/longest
C) weakest/shortest
D) weakest/longest
E) intermediate in both strength and length
39. Of the possible bonds between carbon atoms (single, double, and triple), __________.
A) a triple bond is longer than a single bond
B) a double bond is stronger than a triple bond
C) a single bond is stronger than a triple bond
D) a double bond is longer than a triple bond
E) a single bond is stronger than a double bond
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