Answer Key
Chem 10113, Quiz 2
September 14, 2016
IA
VIIIA
(1)
(18)
1
1
2
3
4
5
IIA
IIIA
IVA
VA
VIA
VIIA
1.0080
(2)
(13)
(14)
(15)
(16)
(17)
3
4
5
6
7
8
9
10
Li
Be
B
C
N
O
F
Ne
15
16
P
S
33
34
As
Se
51
52
Sb
Te
6.9410
9.0122
10.811
12.011
11
12
13
14
Na
22.990
Mg
IIIB
24.305
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
26.982
28.086
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Mn
Fe
43
44
Tc
Ru
K
7
Ca
Sc
IVB
VB
VIB
Ti
V
Cr
39.098
40.078
44.956
47.880
50.942
51.996
37
38
39
40
41
42
Rb
85.468
6
2
H
Sr
87.620
Y
88.906
Zr
91.224
Nb
92.906
Mo
95.940
VIIB
. . . . . . . . . . VIIIB . . . . . . . . .IB
.
54.938 55.847
98.907 101.07
Co
Ni
IIB
Cu
Zn
Al
Ga
Si
Ge
58.933
58.690
63.546
65.380
69.723
72.610
45
46
47
48
49
50
Rh
102.91
Pd
106.42
Ag
107.87
Cd
112.41
In
114.82
Sn
118.71
14.007 15.999
30.974 32.066
74.922 78.960
121.75 127.60
He
4.0026
18.998
20.179
17
18
Cl
Ar
35.453
39.948
35
36
Br
Kr
79.904
83.800
53
54
I
126.90
Xe
131.29
55
56
57
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
132.91
137.33
138.91
178.49
180.95
183.85
87
88
89
104
Unq
105
Unp
106
Unh
107
Uns
261.11
262.11
263.12
262.12
Fr
223.02
Ra
226.03
Ac
227.03
196.97
200.59
204.38
207.20
208.98 208.98
209.99
59
60
61
62
63
64
65
66
67
68
69
70
71
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
140.91
144.24
145.91 150.36
90
91
92
93
94
Th
Pa
U
Np
Pu
231.04
238.03
237.05 244.06
151.97
157.25
95
96
Am Cm
243.06
247.07
158.93 162.50
164.93
167.26
168.93 173.04
174.97
97
98
99
100
101
102
103
Bk
Cf
Es
Fm
Md
No
Lr
247.07 242.06
252.08
Circle any of the following that are ionic compounds.
As4S3
Na3N
IF7
Cl3SiH
Al2O3
257.10
258.10 259.10
222.02
260.11
(2 points)
(3 points)
OF2
NH4F
Write complete chemical formulas for the following ions.
(a) peroxide
3.
195.09
58
232.04
2.
192.22
Ce
140.12
1.
186.21 190.20
O22-
(d) chromate
-
(b) thiocyanate
SCN
(c) hydronium
H3O+
(e) acetate
(f) azide
CrO42-
C2H3O2
N3
-
SHOW ALL WORK. The specific gravity of silver (Ag) is 10.5. Determine the number
of Ag atoms in a small sphere of pure Ag with a radius of 0.00150 inch. (Note: The volume of a
sphere of radius R equals (4/3)R3.)
(4 points)
R = (0.00150 in) (2.54 cm/in) = 0.00381 cm
V = (4/3) (3.1416) (0.00381 cm)3 = 2.316 x 10-7 cm3
(2.316 x 10-7 cm3) (10.5 g/cm3) (1 mole Ag / 107.87 g) (6.022 x 1023 atoms/mole)
= 1.36 x 1016 Ag atoms
4.
(9 points)
Write the chemical formula for each of the following compounds.
Name
Formula
(NH4)2S2O3
ammonium thiosulfate
HIO4(aq)
periodic acid
Ni3(PO4)28H2O
nickel(II) phosphate octahydrate
XeF6
xenon hexafluoride
Ca(MnO4)2
calcium permanganate
C3H8
propane
AlP
aluminum phosphide
5.
mercury(I) nitrate
Hg2(NO3)2
hydrotelluric acid
H2Te(aq)
Write a complete, balanced chemical equation for the reaction of nitric acid with
cobalt(III) hydroxide.
(2 points)
3 HNO3
6.
+
Co(OH)3

Co(NO3)3
+
3 H2O
SHOW ALL WORK. Aluminum carbide, a high-tech ceramic material, is a binary
compound of aluminum and carbon. When a 2.011-g sample of aluminum carbide was completely
combusted with oxygen, 2.850 g of solid Al2O3 (molar mass = 101.9) was produced along with an
undetermined quantity of CO2 gas. Determine the empirical formula of aluminum carbide. (Note:
To receive any partial credit, you must use the mole concept!)
(5 points)
(2.850 g Al2O3) (1 mole / 101.9 g) (2 mole Al / 1 mole Al2O3) = 0.05594 mole Al
(0.05594 mole Al) (26.98 g/mole) = 1.509 g Al
mass C = 2.011 g sample - 1.509 g Al = 0.5018 g C
(0.5018 g C) (1 mole / 12.01 g) = 0.04178 mole C
Al0.05594 C0.04178 = Al1.33 C = Al3C4