Chem 6A 2011 (Sailor)
QUIZ #1
Name:
Student ID Number:
Section Number:
VERSION A KEY
1
18
1
H
2
2
1.0079
3
13
14
15
6.941 9.01218
11
12
10.811
13
12.011 14.0067 15.9994 18.9984 20.1797
14
15
16
17
18
Al
Si
Na Mg
22.9898
19
K
39.0983
37
Rb
85.4578
55
Cs
B
3
24.305
20
Ca
4
21
Sc
40.078 44.9559
38
39
Sr
Y
87.62 88.9059
56
57
Ba
La
132.905 137.327 138.906
87
88
89
Fr
Ra
5
22
23
Ti
7
24
V
8
25
Cr
Zr
Hf
Ta
W
Co
55.847 58.9332
44
45
Ru
95.94 98.9063
74
75
178.49 180.948
104
105
10
27
Fe
Nb Mo Tc
91.224 92.9064
72
73
9
26
Mn
47.88 50.9415 51.9961 54.9381
40
41
42
43
Rh
101.07 102.906
76
77
Re
Os
183.85 186.207
106
107
Ir
190.2
108
192.22
109
28
Ni
58.69
46
Pd
11
29
Cu
63.546
47
Ag
12
N
P
26.9815 28.0855 30.9738
30
31
32
33
Zn
65.39
48
Cd
Ga
69.723
49
Ge
As
72.61 74.9216
50
51
In
Sn
Sb
106.42 107.868 112.411
78
79
80
114.82
81
118.71
82
121.75
83
Pt
Tl
Pb
Au Hg
195.08 196.967
200.59 204.383
207.2
Bi
58
Lanthanides
59
60
-
S
F
Cl
61
62
63
64
65
Pr
Nd Pm Sm Eu
Gd
Tb
140.12
90
140.91
91
144.24
92
157.25
96
158.92
97
Th
Pa
231.04
U
238.03
146.92
93
150.35
94
151.96
95
66
67
Dy Ho
162.5
98
Se
Kr
78.96
52
Te
Br
79.904
53
I
Po
At
71
168.93
101
174.97
103
Fm Md No
Cf
Es
254.09
249.08
70
167.26
100
251.08
247.07
69
164.93
99
Pu Am Cm Bk
257.1
258.1
Some useful constants and relationships:
Specific heat capacities (in J/g.K): H2O(l) = 4.184; Al(s) = 0.900; Cu(s) = 0.387; Steel(s) = 0.45
101.325 J = 1 L.atm
1 atm = 760 Torr
1J = 1kg.m2/s2
1 eV = 1.6022 x 10-19J
.
.
-1 . -1
.
-1 . -1
R = Ideal gas constant: 0.08206 L atm mol K = 8.31451 J mol K
Avogadro constant: 6.022 x 1023 mole-1
Planck's constant = h = 6.6261 x 10-34 J.s
8
c = speed of light: 3.00 x 10 m/s
RH = 1.097 x 10-2 nm-1
-2
.
C2 = second radiation constant = 1.44 x 10 K m
1
Emitted power (W)
Tλmax = C2
= (constan t)T 4
e = mc 2
c = λν
5
Surface area (m2 )
⎛ 1
⎛ Z 2 ⎞
1
1 ⎞
hc
= R H ⎜ 2 − 2 ⎟
E = hν
E=
E(in Joules) = −2.18 ×10−18 ⎜ 2 ⎟
λ
λ
⎝ n ⎠
⎝ n1 n 2 ⎠
131.29
86
Rn
208.98 208.982 209.987 222.018
Lu
239.05
83.8
54
Xe
127.6 126.905
84
85
Tm Yb
237.05
Ar
39.948
36
Er
Np
241.06
68
Ne
32.066 35.4527
34
35
-
Ce
232.038
€
O
9
Ac
223.02 226.025 227.028 -
Actinides
6
C
8
4.0026
10
5
Be
7
He
17
4
Li
6
16
173.04
102
255
Lr
262.1
Chem 6A 2011 (Sailor)
QUIZ #1
1. Fill in the blanks in the following table: (4 pts ea)
Symbol (including
the mass number)
28
Si
88
Number of Protons
Number of Neutrons
Number of
Electrons
14
14
14
38
50
36
Sr2+
2. A mass spectrometer was used to measure the mass of an unknown isotope. The ratio
of the mass of the unknown isotope to the mass of 12C (i.e., the mass ratio) is 2.3314.
The relative abundance of the unknown isotope is 92.1%, and the relative abundance
of 12C is 98.9%. What is the mass of the unknown isotope? Set up the problem but do
not solve it. (10 pts)
Mass (amu) = (mass of 12C) x (mass unknown/mass 12C) = (12.00 x 2.3314)
Numerically the answer is 27.9768 AMU
+2 points if 12.00 (not 12.011 is used)
+2 points if 2.3314 is there (even if they divide by it instead of multiplying)
+6 points if their answer calculates to 27.9868
most common error will be to include the % abundance numbers in the calcultion. If that
is the case, they should get only 2 points if they use 12 and not 12.011 (they recognize
that 12C is the standard mass reference). Otherwise they should get 0 points.
3. Give the name and the empirical formula for the ionic compound formed from the
following pairs of elements. The first one is done for you (4 pts each):
Elements
Magnesium and nitrogen
Formula
Mg3N2
Name
Magnesium nitride
Iodine and cadmium
CdI2
Cadmium iodide
Strontium and fluorine
SrF2
Strontium fluoride
Sulfur and cesium
Cs2S
Cesium sulfide