1. Art and Diseño

Copyright RJZ 1/30/15
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Chemistry 1250 - Sp15
Practice Midterm 1
Copyright RJZ 1/30/15
1.
2.
If only one substance is present the material must be uniform throughout.
Some pure substances can be decomposed into simpler pure substances.
Heterogeneous mixtures may not contain elements.
Every compound is a pure substance.
A heterogeneous mixture must contain at least two different substances.
Choose from the following list those properties that are physical properties of zinc.
A.
B.
C.
D.
E.
a) A
3.
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Which of the following statements is INCORRECT?
a)
b)
c)
d)
e)
This material is copyrighted. Any use or reproduction is not allowed except with the expressed written permission
of Dr. Zellmer. If you are taking Chem 1250 you are allowed to print one copy for your own use during the
semester you are taking Chem 1250 with Dr. Zellmer. You are not allowed to disseminate this material to anyone
else during the semester or in the future.
2
It corrodes in moist air.
It is a grey metal.
It melts at 419EC.
It reacts with acid to give hydrogen gas
It conducts electricity.
b) C
c) A, D
d) C, E
e) B, C, E
Do the indicated arithmetic and give the answer to the correct number of significant figures.
(14.9 x 0.049) - (3.53 ÷ 0.0840) + 121.600
a) 80.295
4.
c) 8.0 x 101
b) 80.29
d) 80
e) 80.3
A crucible is known to weigh 24.3162 g. Three students in the class determine the weight of the crucible
by repeated weighings on a simple balance. Which of the conclusions summarizes the data?
Student A
Student B
Student C
a)
b)
c)
d)
e)
trial 1
24.8
24.6
24.5
trial 2
24.9
24.0
24.1
trial 3
24.7
24.2
24.5
trial 4
24.9
24.1
24.1
trial 5
24.8
24.3
24.3
student B has done the most precise work and student C the most accurate
student B has done the most precise work and student A the most accurate
student C has done the most precise work and student B the most accurate
student C has done the most precise work and student A the most accurate
student A has done the most precise work and student C the most accurate
Copyright RJZ 1/30/15
5.
3
Alka Seltzer tablets contain 2.1 x 10 mg of sodium bicarbonate. How many tablets can be made from
5.5 kg of sodium bicarbonate?
a) 2.6 x 105
b) 2.6 x 104
3
2
d) 5.1 x 10
6.
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8.
c) 2.6 x 103
4
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A 27.40-g sample of osmium is placed in a graduated cylinder containing 40.00 mL of water and the water
level rises to 41.22 mL. What is the density (in g/cm3) of the sample of osmium? (Look closely at the
answers & be careful!)
a) 33.43
b) 33.4
c) 22.46
d) 22.5
e) 0.045
e) 5.1 x 10
The lethal dose of the drug strychnine taken orally is 5.0 mg per kilogram of body weight in rats.
Calculate the lethal dose in grams for a 140 lb person, assuming that a human functions the way rats do.
(1 lb = 453.6 g)
a) 0.11
7.
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3
b) 0.32
c) 0.65
d) 1.5
9.
Which of the following is the HIGHEST temperature?
a) -4EF
b) -25EC
c) 250 K
e) 28
The world's oceans contain approximately 1.4 x 109 km3 of water. What is the volume in liters?
a) 1.4 x 1027
b) 1.4 x 1021
d) 1.4 x 1015
e) 1.4 x 1012
c) 1.4 x 1018
10.
Select the combination of statements which are CORRECT.
1) The mass number of an atom is the sum of the number of neutrons and protons in the nucleus.
2) The number of neutrons in atom is its atomic number.
3) The number of electrons and protons in a neutral atom are equal.
4) The volume occupied by the nucleus is a small percentage of the total volume of the atom.
5) Isotopes of an element differ only in the number of protons.
a) 2, 3
b) 1, 3, 4
c) 1, 2, 3
d) 1, 4, 5
e) 4, 5
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11.
5
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Rubidium (atomic weight 85.4678) has two naturally-occurring isotopes, the predominant one being 85Rb
Copyright RJZ 1/30/15
14.
with isotopic weight 84.9117 and an abundance of 72.15%. Which of the following isotopic weights is
the most likely for the other isotope? (Hint: You are solving for the mass of this other isotope.)
a) 89.8999
b) 88.9201
c) 87.9124
d) 86.9092
+
a) 3
15.
12.
Fe2(CO3)3
b) sulfur hexafluoride,
SF6
c) diphosphorus tetroxide,
P2O4
d) zirconium (IV) iodate,
Zr4(IO3)
e) zinc bisulfate,
Zn(HSO4)2
BiCl3 +
a) 11
16.
13.
Yttrium nitrate is Y(NO3)3. What are the formulas of yttrium carbonate and yttrium arsenate? (Assume
the charge on the yttrium has the same charge in all compounds.)
a) Y2(CO3)3, YAsO4
b) YCO3, YAsO4
c) Y3(CO3)2, Y3AsO4
d) Y2(CO3)3, Y2(AsO4)3
e) YCO3, Y2(AsO4)3
NH3
+
b) 4
H2O
v
c) 5
Fe(OH)3
+
d) 6
NH4NO3
e) 7
Balance the following equation. What is the sum of the coefficients of the reactants AND
products. (If present, don't forget the coefficients of 1.)
Which of the following pairs of names and formulas is INCORRECT?
a) iron (III) carbonate,
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Balance the following equation and choose the answer which is the sum of the coefficients of the
REACTANTS. (If present, don't forget the coefficients of 1.)
Fe(NO3)3
e) 85.9142
6
NH3 +
v
H2 O
b) 10
Bi(OH)3 +
c) 9
NH4Cl
d) 7
e) 4
Balance the following equation and choose the quantity which is the sum of the coefficients of
REACTANTS AND PRODUCTS. (If present, don't forget the coefficients of 1.)
NH3
a) 12
b) 15
+
O2
c) 19
v
NO
d) 20
+
H2 O
e) 22
Copyright RJZ 1/30/15
17.
18.
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Carbonic anhydrase, which catalyzes the interconversion of carbon dioxide and hydrogen carbonate to
maintain acid balance in blood, contains one zinc atom per molecule and the zinc is 0.121% by mass.
What is the molar mass (g/mole) carbonic anhydrase? (Atomic weight: Zn - 65.38)
a) 5.40 x 104
b) 7.91 x 104
d) 5.40 x 102
e) 7.91 x 102
Copyright RJZ 1/30/15
20.
c) 1.67 x 104
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A 0.589 g sample of an organic compound containing only carbon, hydrogen and oxygen was burned
completely in air to produce 0.733 g of CO2 and 0.299 g of H2O. What is the empirical formula of the
compound? (Atomic weights: C = 12.01, H = 1.008, O = 16.00)
a) C2H4O2
b) C3H6O5
c) C3H5O2
d) C3H6O2
Cisplatin, an anticancer drug, has the molecular formula Pt(NH3)2Cl2. How many moles of
hydrogen atoms are in 2.8 x 10-4 g of cisplatin?
(At. wts: Pt = 195.1, H = 1.008, N = 14.01, Cl = 35.45 ; Mol. wt: 300.07)
a) 5.6 x 10-6
b) 5.6 x 10-3
d) 2.8 x 10-3
e) 2.8 x 10-6
c) 1.9 x 10-6
21.
19.
8
Which of the following are weak electrolytes?
Potassium carbonate has the formula, K2CO3. How many potassium ions are present in
0.10 g of K2CO3?
(At. Wts.: C = 12.01, O = 16.00, K = 39.10; Form. Wt.: K2CO3 = 138.21)
H3PO4
a) 8.7 x 1020
b) 1.7 x 1025
a) H3PO4, NH3, Ni(NO3)2
d) 4.4 x 1021
e) 8.3 x 1024
c) 4.4 x 1020
HNO3
Ni(NO3)2
b) H3PO4, NH3
c) HNO3, Ni(NO3)2, NaOH
d) HNO3, Ni(NO3)2, NH3
e) none are weak electrolytes
NaOH
NH3
e) C3H6O4
Copyright RJZ 1/30/15
22.
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Barium hydroxide reacts with phosphoric acid according to the following equation. Which substance is
the limiting reagent when 0.50 mol of Ba(OH)2 reacts with 0.50 mol of H3PO4? How many moles of the
excess reagent remain after completion of the reaction?
Copyright RJZ 1/30/15
25.
3 Ba(OH)2 (s) + 2 H3PO4 (aq) v Ba3(PO4)2 (aq) + 6 H2O (R)
a) H3PO4 ; 0.17
b) H3PO4 ; 0.33
d) Ba(OH)2 ; 0.25
e) Ba(OH)2 ; 0.33
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Solutions of lead(II) nitrate and potassium chromate are mixed. Select the correct NET IONIC
reaction from those given below.
a) No reaction occurs
b) Pb2+ + 2 NO3! 6 Pb(NO3)2
c) Ba(OH)2 ; 0.17
c) Pb2+ + CrO42! 6 PbCrO4
d) 2 K+ + 2 NO3! 6 2 KNO3
e) 2 K+ + CrO42! + Pb2+ + 2 NO3! 6 2 K+ + 2 NO3! + PbCrO4
26.
What are the expected products of the following reaction?
CaCO3 (s) + H2SO4 (aq)
23.
v
a) Ca(OH)2 + SO3 + CO2
Which of the following is (are) an example(s) of an single-replacement (displacement) reaction
(assume all reactons occur to give products)?
b) CaSO4 + H2 + CO3
1) Al (s) + Cl2 (g) 6
c) 4 CaO + 4 CO2 + H2S
2) Pb(NO3)2 (aq) + NH4Cl (aq) 6
d) CaCO3H2SO4
3) PCl3 (g) + Cl2 (g) 6
e) CaSO4 + H2O + CO2
4) Zn (s) + HCl (aq) 6
5) HCl (aq) + CaS (aq) 6
a) 2 only
24.
b) 3 only
c) 4 only
d) 1 and 4
e) 2 and 5
Which of the reactions in question 23 is (are) an example(s) of a combination reaction (assume all
reactions occur to give products)?
a) 1 only
b) 3 only
c) 4 only
d) 1 and 3
e) 2 and 5
27.
What volume of 0.141 M H3PO4 is required to neutralize 50.0 mL of 0.0521 M Mg(OH)2 ?
3 Mg(OH)2 + 2 H3PO4
a) 27.1 mL
b) 12.3 mL
v
c) 40.6 mL
Mg3(PO4)2 + 6 H2O
d) 18.1 mL
e) 35.8 mL
Copyright RJZ 1/30/15
28.
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Copyright RJZ 1/30/15
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USEFUL INFORMATION
Arrange the following phosphorus containing species in order of increasing oxidation number of
the phosphorus atom. What compound occupies the intermediate (middle) position?
a) P4
b) PH2
&
c) HPO3
2&
d) P2H4
e) PO4
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1 in = 2.54 cm
3&
1 mile = 5280 ft
1 lb = 453.6 g
1 qt = 946 mL
1 lb = 16 oz
1 amu = 1.66 x 10-24 g
Avogadro's number = 6.02 x 1023 particles/mole
29.
-10
1 Å = 1 x 10
Which of the following represent redox reactions?
-8
m = 1 x 10 cm
1. Cu(OH)2(s) + 2 HNO3 (aq) 6 Cu(NO3)2 (aq) + 2 H2O(R)
2. Cl2(aq) + 2 NaI (aq) 6 I2 (aq) + 2 NaCl(aq)
IA
3. 3 Fe(NO3)2(aq) + 2 Al(s) 6 3 Fe(s) + 2 Al(NO3)3 (aq)
a) 1 and 2
b) 2 and 3
c) 1 and 3
IIA
IIIB
IVB
VB
VIB
VIIB
VIIIB
IB
IIB
d) all
e) none
2
IVA
VA
VIA
4
9.012
Be
10.811 12.011 14.007 15.999 18.998 20.179
B
C
N
O
F
Ne
5
6
7
8
9
10
4
22.990 24.305
Na
Mg
12
39.098
K
19
5
Examine the reaction below and the statements concerning the reaction. Select an answer which
includes ALL of the CORRECT statements given below.
85.47
Rb
37
6
26.98
Al
40.08
Ca
20
44.96
Sc
21
87.62
Sr
38
13
88.91
Y
39
47.88
Ti
22
81.22
Zr
40
50.94
V
23
92.91
Nb
41
52.00
Cr
24
54.94
Mn
25
95.94
Mo
42
55.85
Fe
26
98
Tc
43
58.93
Co
27
28.09
Si
14
30.974
P
15
32.06
S
16
58.69 63.546 65.38 69.72 72.59 74.92 78.96 79.904 83.80
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
29
30
31
32
33
34
35
36
101.07 102.91 106.42 107.87 112.41 114.82 118.69 121.75 127.60 126.90 131.39
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
45
46
47
48
49
50
51
52
53
54
44
132.91 137.33 138.91 178.39 180.95 183.85 186.21 190.23 192.22 195.08 196.97 200.59 204.38 207.2 208.98 209
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
56
57
72
73
74
75
76
77
78
79
80
81
82
83
84
1)
2)
3)
4)
5)
+
20 BrF3
v
12 IF5
+
15 O2
+
b) 3
c) 2, 3
226.03 227.03
261
Ra
Ac
Rf
89
104
88
262
Ha
105
263
Sg
106
262
Ns
107
265
Hs
108
266
Mt
109
269
110
272
111
210
At
85
277
112
10 Br2
Br has been oxidized.
F is reduced.
The oxidation number of Br changed from +3 to 0.
O has been oxidized.
The oxidation number of F changed from -1 to 0.
a) 2, 4
223
Fr
87
35.453 39.948
Cl
Ar
18
17
28
55
7
d) 3, 4
VIIIA
4.003
He
11
6 I 2 O5
VIIA
2
6.941
Li
3
3
30.
IIIA
1.008
1
H
1
140.12 140.91 144.24
145
Ce
Pr
Nd
Pm
59
60
61
Lanthanide
Series
58
Actinide
Series
90
150.36 151.96 157.25 158.93 162.50 164.93 167.26 168.93 173.04 173.04
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
63
64
65
66
67
68
69
70
71
62
232.04 231.04 238.03 237.05
Th
Pa
U
Np
Pu
91
92
93
94
Am
95
Cm
96
Bk
97
Cf
98
A PERIODIC CHART OF THE ELEMENTS
(Based on 12C)
e) 1, 3, 5
Copyright R. J. Zellmer, January 30, 2015
Es
99
Fm
100
Md
101
No
102
Lr
103
222
Rn
86
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Copyright RJZ 1/30/15
SOLUBILITY
Soluble
None
nitrates, acetates, chlorates,
perchlorates, permanganates
Soluble
None
chlorides, bromides, iodides
Soluble
Cmpds of Ag+, Hg22+, Pb2+,
Hg2+ iodide and Hg2+ bromide
sulfates
Soluble
Cmpds of Sr2+, Ba2+, Hg22+, Pb2+
hydroxides, oxides, sulfides
Insoluble
Cmpds of alkali metals (grp 1A) , ammonium,
Ca2+, Sr2+, Ba2+
sulfites, carbonates, phosphates, chromates
Insoluble
Cmpds of alkali metals (grp 1A) , ammonium
Copyright R. J. Zellmer, January 30, 2015
Answers to Practice Midterm 1
IMPORTANT EXCEPTIONS
alkali metal (grp 1A)
ammonium
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Chemistry 1250
EMPIRICAL RULES FOR THE SOLUBILITY OF IONIC SOLIDS IN H2O
COMPOUNDS CONTAINING
14
1) C
11) D
21) B
2) E
12) D
22) C
3) E
13) A
23) C
4) E
14) E
24) D
5) C
15) A
25) C
6) B
16) C
26) E
7) B
17) A
27) B
8) D
18) A
28) A
9) A
19) A
29) B
10) B
20) E
30) D