University of Saskatchewan
Department of Chemistry
CHEMISTRY 112.3
Deferred Midterm Examination
T1: 2012-2013
Last Name (please print clearly!)____________________________________________
Given Name (please print clearly!)_____________________________________________
Student Number
Signature___________________________________
Please indicate your section:
Section 01
Section 03
Section 05
Section 97
Section C11
Section C15
MWF 8:30 AM
MWF 9:30 AM
TTh 10:00 AM
Muenster
Melfort
Prince Albert
Dr. K. Brown
Dr. S. Urquhart
Dr. R. Scott
Dr. A. Szmigielski
Dr. A. Szmigielski
Dr. R. Catton
INSTRUCTIONS - PLEASE READ THIS FIRST!
1. This is a closed-book examination. A data-sheet with a Periodic Table is attached to the last page of this
examination paper (you can remove this page from the booklet for convenience)
2. Simple scientific calculators are permitted. Alphanumeric calculators and those capable of storing
equations are not permitted. Cell phones, personal digital assistants, electronic dictionaries, etc. are not
allowed. No equations may be stored in memory of electronic devices.
3. This examination paper has 11 pages, including the data sheet. To ensure that your copy is complete and to
become familiar with the questions, please read through the entire examination before you answer any
questions.
4. You can use the backside of the 11 pages as scratch paper.
5. A total of 100 marks can be obtained. Each of the 40 questions will be weighted with 2.5 marks each. You
should spend an average of 3 minutes on each question.
6. Please fill out the top of this paper and the top of the blue op-scan sheet. Print your name and code
your student number in soft pencil.
7. Answer these questions by circling the response on this paper AND by filling out the corresponding
response on the blue opscan sheet USING A SOFT-LEAD PENCIL ONLY. No deductions will be made
for incorrect answers, but multiple answers will be treated as NO answer. If you change your mind, erase
the incorrect answer carefully from the blue optical scan sheet. In the event of a discrepancy, the
response on the opscan sheet will count.
8. HAND-IN ALL of your material (question sheet and computer sheet)
1. The molar mass of cinnamic acid, C9H8O2, is
a.) 24 g/mol
b.) 148 g/mol
c.) 180 g/mol
d.) 230 g/mol
e.) 19 g/mol
2. How many significant figures does the result of the following operation contain?
99.5201 / (6.91 – 7.20)
a.) 1
b.) 2
c.) 3
d.) 4
e.) 5
3. Which of the following represents the largest number of moles?
a.) 1.00 g H2
b.) 1.00 g He
c.) 1.00 g C
d.) 1.00 g Zn
e.) 1.00 g Fe
4. Element “X” has two isotopes. Isotope 1 has atomic mass 310.22 u and an abundance of 10.50% and
isotope 2 has atomic mass 350.95 u and an abundance of 89.50%%. What is the average atomic mass of
element “X”?
a.) 346.7 u
b.) 330.6 u
c.) 310.2 u
d.) 351 u
e.) none of the above
5. A main group element M that forms ionic compounds containing the M1+ ion is
a.) Mg
b.) N2
c.) S
d.) Mn
e.) Cs
2
6. An element M is found to contain 5.67 x 1020 atoms in a sample of 61.6 mg of the element. What is
the molar mass in g/mol of the element M?
a.) 65.4 g/mol
b.) 65.42 g/mol
c.) 6542 g/mol
d.) 6542.18 g/mol
e.) 6.542 x 1020 g/mol
7. An example of a homogeneous mixture is
a.) a liquid solution composed of isopropyl alcohol and water
b.) a handful of wet beach sand
c.) a sample of air
d.) both a and b are correct
e.) both a and c are correct
8. How many hydrogen atoms are in 0.50 mols of cinnamic acid, C9H8O2?
a.) 8
b.) 4
c.) 4.82 x 1024
d.) 6.02 x 1023
e.) 3.22 x 1025
9. Osmium metal has a density of 22.59 g/cm3 at room temperature. What volume does 3.39 kg of
osmium occupy?
a.) 150 cm3
b.) 0.150 cm3
c.) 3.41 cm3
d.) 3.41 x 10-3 cm3
e.) 223 cm3
10. The isotope iron-57 has how many neutrons in it's nucleus?
a.) 31
b.) 55.85
c.) 20
d.) 17
e.) 0
3
11. Nicotine has the following elemental mass percent composition: C 74.03%, H 8.70%, N 17.27%.
The molar mass of nicotine is 162 g/mol. What is the molecular formula for nicotine?
a.) C12H4N1
b.) C9H12N3
c.) C10H28N
d.) C8H10N4
e.) C10H14N2
12. Which of the following name / formula combinations are correct?
i. Potassium Perchlorate
ii. Sodium nitrite
iii. Calcium sulfate hemihydrate
iv. Sulfur pentachloride
v. Sodium hydrogen carbonate
KClO4
NaNO2
CaSO4 . ½ H2O
PCl4
Na2CO3
a.)all of the name / formula combinations
b.) i, iii, and iv
c.)iv and v
d.) i, ii, and iii
e.) ii and iii
13. Select the correct molar mass of sulfurous acid:
a.) 34.08 g/mol
b.) 81.07 g/mol
c.) 97.07 g/mol
d.) 98.08 g/mol
e.) 82.08 g/mol
14. What mass of Cr is found in 1.00 x 102 g of K2Cr2O7?
a.) 35.4 g
b.) 24.3 g
c.) 12.2 g
d.) 48.6 g
e.) 33.8 g
15. What is the mass of sodium in 50.0 g of sodium sulfite?
a.) 29.5 g
b.) 16.2 g
c.) 18.2 g
d.) 11.2 g
e.) none of the above
4
16. Fumaric acid has a molecular formula, C4H4O4. The percent composition of fumaric acid is:
a.) Carbon: 33.33 %
b.) Carbon: 39.80 %
c.) Carbon: 40.00 %
d.) Carbon: 41.39%
e.)Carbon: 0.25 %
Hydrogen: 33.33 %
Hydrogen: 6.68 %
Hydrogen: 6.67 %
Hydrogen: 3.47 %
Hydrogen: 0.25 %
Oxygen: 33.33 %
Oxygen: 53.52 %
Oxygen: 53.33 %
Oxygen: 55.14 %
Oxygen: 0.50 %
17. A compound has the following percentage composition, by weight: 38.7%, 13.8% N, and 47.5% O.
What is the empirical formula of this compound?
a.) KNO3
b.) KNO2
c.) K2NO2
d.) K2NO3
e.) K2N2O3
18. What are the coefficients of reactants and products, respectively, when the equation shown below is
balanced?
____CH4 + ____ O2 ____ CO2 + ____ H2O (unbalanced)
a.) 0, 2, 0, 1
b.) 1, 1, 1, 2
c.) 1, 2, 1, 2
d.) 2, 2, 1, 4
e.) none of the above
19. What are the coefficients of Al and S, respectively, when the equation shown below is balanced with
the smallest possible integers?
____ Al (s) + ____ S8 (s) ____ Al2S3 (s) (unbalanced)
a.) 16, 3, 8
b.) 2, 3, 1
c.) 16, 24, 8
d.) 2, 24, 1
e.) none of the above
5
20. A solution containing 10 g of Pb(NO3)2(aq) is mixed with a solution containing 5.0 g of KI(aq).
Which of the following is true?
a.) The limiting reagent is Pb(NO3)2(aq).
b.) The limiting reagent is KI.
c.) No reaction occurs.
d.) There is no excess reactant.
e.) None of the above.
21. When equal volumes of 0.2 M solutions are mixed, which of the following combinations will form
a precipitate?
a.) CuCl2(aq) + NH4NO3(aq)
b.) MgSO4(aq) + K2CO3(aq)
c.) Na2S(aq) + LiClO4 (aq)
d.) FeCl3(aq) + CuSO4(aq)
e.) none of the above
22. The distinguishing characteristic of all electrolyte solutions is that they:
a.) contain ions
b.) are electric insulators
c.) react with other solutions
d.) always contain acids
e.) none of the above
23. 1 mole of PCl3 is produced from the reaction of solid elemental phosphorous, P(s), with excess
chlorine gas. Determine the moles of phosphorous required for this reaction if the yield is 25%?
a.) 1 mol
b.) 2 moles
c.) 4 moles
d.) 0.25 moles
e.) None of the above
24. 0.500 L of a 0.500 M MgCl2 solution is diluted with an additional 1.500 L of water to give a final
solution with volume 2.000 L. What is the final [Cl-] concentration?
a.) 0.125 M
b.) 0.250 M
c.) 0.500 M
d.) 0.0625 M
e.) Impossible to predict
6
25. If 10.0 mL of 1.00 M HCl is added to 190.0 mL of water. Following this, 25.0 mL of the new
solution is removed. How many moles of HCl are in the 25.0 mL sample?
a.) 0.00125 mol
b.) 0.0125 mol
c.) 0.0100 mol
d.) 0.050 mol
e.) None of the above
26. Consider the following balanced reaction:
4 CaSO4(s) + 3 CH4(g) + CO2(g) → 4 CaCO3(s) + 4 S(g) + 6 H2O(g)
11.0 moles of CaSO4(s), 9.0 moles of CH4 and 5.0 moles CO2 are allowed to react. Assume the reaction
goes to the maximum extent possible. How many moles of water are produced?
a.) 11.0 mol
b.) 12.5 mol
c.) 14.5 mol
d.) 16.5 mol
e.) Cannot be determined from the above.
27. What will precipitate when sodium hydroxide and copper (II) bromide are mixed?
A.) Copper (II) hydroxide only
B.) Sodium bromide only
C.) Copper (II) bromide only
D.) Both copper(II) hydroxide and sodium bromide
E.) No reaction will occur
28. Which are the “spectator ions” in the following neutralization reaction?
Sr(OH)2(aq) + 2 HBr(aq) → SrBr2(aq) + 2 H2O(l)
a.) Sr2+ and H+
b.) OH- and Brc.) Sr2+ and Brd.) H+ and OHe.) Sr2+ and OH-
7
29. A 25.05-mL sample of 0.586 M NaOH solution is required to neutralize the CH3COOH in a 10.0-mL
sample of vinegar according to the following equation:
NaOH(aq) + CH3COOH(aq) → CH3COONa(aq) + H2O(l)
What is the molarity of CH3COOH in the sample?
a.) 0.996 M
b.) 1.47 M
c.) 1.89 M
d.) 2.06 M
e.) 2.55 M
30. How many milliliters of 0.712 M HCl solution are required to titrate a 10.0-mL sample of 0.556 M
Al(OH)3 solution?
a.) 10.5 mL
b.) 15.2 mL
c.) 17.0 mL
d.) 23.4 mL
e.) 25.1 mL
31. The oxidation states of Na, Cl and O in the molecule of NaClO3 are:
a.) Na is +1, Cl is -1, O is -2
b.) Na is +1, Cl is +1, O is -1
c.) Na is +1, Cl is +3, O is -2
d.) Na is +1, Cl is +5, O is -2
e.) Na is +1, Cl is +7, O is -2
32. Arrange HNO3, NH3 and N2O3 in order of increasing oxidation state of the N atom (e.g. more
positive).
a.) HNO3, NH3, N2O3
b.) NH3, HNO3, N2O3
c.) HNO3, N2O3, NH3
d.) NH3, N2O3, HNO3
e.) N2O3, HNO3, NH3
33. Which of the following is NOT an oxidation-reduction reaction?
a. 2 Pb(NO3)2(s) → 2 PbO(s) + 4 NO2(g) + O2(g)
b. HNO3(aq) + KOH(aq) → KNO3(aq) + H2O(l)
c. Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2 (g)
d. 2 NO2(g) + 7 H2(g) → 2 NH3(g) + 4 H2O(g)
e. 2 Na(s) + 2 H2O(l) → 2 NaOH(aq) + H2(g)
8
34. Identify the oxidizing agent in the following redox reaction.
MnO2(s) + 4 H+(aq) + 2 Cl-(aq) → Mn+2(aq) + 2 H2O(l) + Cl2(g)
a.) MnO2
b.) H+
c.) Cld.) Mn2+
e.) Cl2
35. A 40.2 L constant-volume container containing 2.21 mol He is heated until the pressure reaches 4.2
atm. What is the final temperature?
a.) 258 K
b.) 658 K
c.) 931 K
d.) 804 K
e.) 1074 K
36. Which of the following is true for 2.24 L of ammonia gas at 2.0 atm and 0°C, assuming it obeys
the ideal gas law?
a.) It contains 0.50 mole NH3
b.) It weighs 1.70 g
c.) It contains 6.02 x1022 molecules of NH3
d.) It contains 3.6 x1023 H atoms
e.) It contains 3.6 x1022 N atoms
37. Diethyl ether was the first general anesthetic. It was first used in 1846 for surgical procedures.
What is the molar mass of diethyl ether if 3.54 grams is 1.06 liters at 27°C and 1.11 atm?
a.) 74.1g/mol
b.) 6.67 g/mol
c.) 103 g/mol
d.) 91.3 g/mol
e.) 4.7 g/mol
38. What volume would be occupied by 4.8 g of oxygen gas at 0.50 atm and 133°C?
a.) 19 L
b.) 13 L
c.) 10 L
d.) 6.7 L
e.) 3.3 L
9
39. What is the density of carbon dioxide gas at -15 °C and 728 torr?
a.) 2.17 gL-1
b.) 2.08 gL-1
c.) 1.84 gL-1
d.) 1.99 gL-1
e) 1.27 gL-1
40. The statement, “for a fixed mass of gas at constant temperature, gas volume is proportional to the
absolute gas temperature” is known as:
A.) Avogadro’s Law
B.) Boyle’s Law
C.) Charles’s Law
D.) Graham’s Law
E.) Kelvin’s Law
10
1
1A
1
H
1.00794
18
8A
Periodic Table of the Elements
2
2A
13
3A
14
4A
15
5A
16
6A
2
17
He
7A 4.00260
3
4
5
6
7
8
9
10
Li
Be
B
C
N
O
F
Ne
6.941
9.01218
10.811
12.011
14.0067
15.9994
18.9984
20.1797
11
12
13
14
15
16
17
18
3
4
Na Mg 3B 4B
22.9898
24.3050
19
20
21
22
5
5B
6
6B
7
7B
8
8B
9
8B
10
8B
11
1B
12
2B
Al
Si
P
S
Cl
Ar
26.9815
28.0855
30.9738
32.066
35.4527
39.948
23
24
25
26
27
28
29
30
31
32
33
34
35
36
K
Ca
Sc Ti
Cr Mn Fe
Co Ni
Cu Zn Ga Ge
As
Se
Br
Kr
39.0983
40.078
44.9559
47.88
50.9415
V
51.9961
54.9381
55.847
58.9332
58.693
63.546
65.39
69.723
72.61
74.9216
78.96
79.904
83.80
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
Rb
Sr
Y
Zr Nb Mo Tc
Ru Rh Pd
Ag Cd In
Sn
Sb
Te
I
Xe
85.4678
87.62
88.9059
91.224
92.9064
95.94
(98)
101.07
102.906
106.42
107.868
112.411
114.818
118.710
121.757
127.60
129.904
131.29
55
56
57
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
Bi
Po
208.980
(209)
Cs Ba La Hf Ta
W
Re
Os
Ir
Pt
Au Hg Tl Pb
132.905
137.327
138.906
178.49
180.948
183.84
186.207
190.23
192.22
195.08
196.967
200.59
87
88
89
104
105
106
107
108
109
110
111
112
114
116
118
(287)
(289)
(293)
Fr
Ra Ac Rf Db Sg
(223)
226.025
227.028
(261)
207.2
At Rn
(210)
(222)
Bh Hs Mt
(262)
(263)
(262)
(265)
(266)
(269)
(272)
(272)
58
59
60
61
62
63
64
65
Ce
204.383
66
67
68
69
70
71
Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
140.115
140.908
144.24
(145)
150.36
151.965
157.25
158.925
162.50
164.930
167.26
168.934
173.04
174.967
90
91
92
93
94
95
96
97
98
99
100
101
102
103
Th Pa
232.038
231.036
U
238.029
Physical Constants
Constant
Atomic mass unit
Avogadro number
Gas Constant
Np Pu Am Cm Bk Cf
237.048
(244)
Symbol
u
NA
R
(243)
(247)
(251)
Value
1.6605 × 10-27 kg
6.0221 × 1023 mol-1
0.082058 L atm mol-1K-1
8.3145 J K-1 mol-1
62.364 L mmHg mol-1 K-1
22.414 L mol-1
9.109 × 10-31 Kg
Molar volume of an ideal gas at STP
Electron mass
Vm
me
Some SI Derived Units
Physical Quantity
Force
Energy
Pressure
Symbol
N
J
Pa
Unit
Newton
Joule
Pascal
(247)
Definition
kg m s-2
kg m2 s-2
N m-2 = kg m-1 s-2
STP Conditions: P = 1 atm = 760 Torr = 760 mmHg = 101.325 kPa
Temperature = 0 ºC = 273.15 K
11
Es Fm Md No Lr
(252)
(257)
(258)
(259)
(260)