2014 Academic Challenge
CHEMISTRY TEST - REGIONAL
This Test Consists of 40 Questions
Chemistry Test Production Team
Jeremy Weaver, Emory University – Author/Team Leader
Nancy Carter Dopke, Alma College – Reviewer
Mary Weaver, WYSE – Coordinator of Test Production
GENERAL DIRECTIONS
Please read the following instructions carefully. This is a timed test; any instructions from the test
supervisor should be followed promptly.
The test supervisor will give instructions for filling in any necessary information on the answer sheet.
Most Academic Challenge sites will ask you to indicate your answer to each question by marking an oval
that corresponds to the correct answer for that question. Only one oval should be marked to answer each
question. Multiple ovals will automatically be graded as incorrect answers.
If you wish to change an answer, erase your first mark completely before marking your new choice.
You are advised to use your time effectively and to work as rapidly as you can without losing accuracy.
Do not waste your time on questions that seem too difficult for you. Go on to the other questions, and
then come back to the difficult ones later if time remains.
*** TIME: 40 MINUTES ***
DO NOT OPEN TEST BOOKLET UNTIL YOU ARE TOLD TO DO SO!
© 2014 Worldwide Youth in Science and Engineering
“WYSE”, “Worldwide Youth in Science and Engineering” and the “WYSE Design” are service marks of and this
work is the Copyright © 2014 of the Board of Trustees of the University of Illinois at Urbana - Champaign.
All rights reserved.
23
24
25
26
27
28
Zr
91.22
72
Y
88.91
57
Sr
87.62
56
Rb
85.47
55
Ti
**Actinides
*Lanthanides
U
238.0
Pa
(231)
Th
232.0
Nd
144.2
92
Pr
140.9
91
60
Uns
Fe
Co
Np
(244)
Pu
Sm
150.4
94
Pm
62
Une
Ni
Eu
63
(243)
Am
Zn
Gd
64
(247)
Cm
Tb
65
(247)
Bk
Ga
Dy
66
(251)
Cf
Ho
67
Es
(252)
Er
68
(257)
Fm
F
O
S
Tm
69
(209)
Po
Md
(258)
Cl
Yb
70
No
(259)
Lu
71
(222)
Rn
131.3
86
Xe
83.80
54
Kr
39.95
36
Ar
20.18
18
Ne
4.003
10
(260)
Lr
175.0
103
(210)
At
126.9
85
I
79.90
53
Br
35.45
35
173.0
102
127.6
84
Te
78.96
52
Se
32.07
34
19.00
17
9
8
16.00
16
7A
6A
168.9
101
209.0
Bi
121.8
83
Sb
167.3
100
207.2
Pb
118.7
82
Sn
As
74.92
51
Ge
30.97
33
P
14.01
15
N
7
5A
72.59
50
28.09
32
Si
12.01
14
C
6
4A
164.9
99
204.4
Tl
114.8
81
In
69.72
49
162.5
98
200.6
Hg
112.4
80
Cd
158.9
97
197.0
Au
107.9
79
Ag
65.38
48
Cu
63.55
47
157.3
96
195.1
Pt
106.4
78
Pd
58.69
46
152.0
95
192.2
109
Ir
102.9
77
Rh
58.93
45
(145)
93
61
Uno
190.2
108
Os
101.1
76
Ru
55.85
44
(237)
186.2
107
Re
(98)
75
Tc
Ce
Unh
183.9
106
W
95.94
74
Mo
Mn
54.94
43
140.1
90
Unp
180.9
105
Ta
92.91
73
Nb
Cr
52.00
42
59
(227)
(223)
V
50.94
41
58
Ac**
Ra
226
Fr
Unq
Hf
178.5
104
La*
138.9
89
Ba
137.3
88
Cs
132.9
87
47.88
40
Sc
44.96
39
Ca
40.08
38
K
39.10
37
30
29
26.98
31
24.31
20
22.99
19
22
Al
Mg
Na
21
10.81
13
9.012
12
6.941
11
5
B
4
Be
Li
3A
2A
1.008
3
H
2
1
He
8A
1A
Periodic Table of the Elements
Potentially Useful Information
q = m • cs • ∆T
∆Tf = i • Kf • m
∆Tb = i • Kb • m
Sgas = kH • Pgas
Psolvent = Χsolvent • P°solvent
k = Ae –Ea/RT
[𝐴]𝑡
� = −𝑘𝑡
[𝐴]0
1
1
−
= 𝑘𝑡
[𝐴]𝑡 [𝐴]0
𝐾2
−∆𝐻𝑟𝑥𝑛 1
1
�=
� − �
𝐾1
𝑅
𝑇2 𝑇1
−∆𝐻𝑣𝑎𝑝 1
𝑃2
1
ln � � =
� − �
𝑃1
𝑅
𝑇2 𝑇1
ln �
[𝐴]𝑡 − [𝐴]0 = − 𝑘𝑡
ln �
pH = -log [H3O+]
[𝐴− ]
pH = pKa + log �[𝐻𝐴]�
∆G° = ∆H° - T∆S°
∆𝐸 = 𝐵 �
1
1
2 − 2�
𝑛𝑓 𝑛𝑖
ln �
𝑘2
−𝐸𝑎 1
1
�=
� − �
𝑘1
𝑅 𝑇2 𝑇1
pOH = -log [OH-]
∆Ssurr =
−∆𝐻𝑠𝑦𝑠
𝑇
Ecell° = Ered° + Eox°
x=
-b ± �b2 - 4ac
2a
∆G° = -nFε°
Kw = 1.0 × 10-14
F = 96485 C/mol
B = -2.18x10-18 J
R = 0.08206 L atm/mol K; 8.3145 J/mol K
NA = 6.022x1023
1.0 kg = 2.2 lb
1 atm = 101,325 Pa = 1.01325 bar
1.0 in = 2.54 cm
1 J = 1 N • m = 1 kg • m2 • s-2 = 0.239 cal
1 lb = 453.59 g
c = λν
c = 2.998 × 108 m/s
Assume all gases behave ideally unless specifically told to do otherwise
Assume all solutions are aqueous and at 25 °C unless specifically told otherwise
Assume all gases are at STP unless specifically told otherwise
Simple Rules for the Solubility of Salts in Water
1. Most nitrates are soluble
2. Most salts containing Group 1 ions or ammonium (NH4+) are soluble
3. Most chloride, bromide, and iodide salts are soluble except those of Ag+, Pb2+, and
Hg22+.
4. Most sulfates are soluble with the exception of Ba2+, Pb2+, Hg22+, and Ca2+
5. Most hydroxide salts are only slightly soluble with the exception of Group 1 hydroxides.
Group 2 (Ba2+ to Ca2+) are slightly soluble.
6. Most sulfides, carbonates, chromates, and phosphates are only slightly soluble.
2014 Regional
WYSE – Academic Challenge
Chemistry Test (Regional) – 2014
1. What mass of phosphorus is present in 3.50 moles of P4O6?
A.
B.
C.
D.
E.
31.0 g
108 g
220. g
434 g
770. g
2. A mixture of oxygen and nitrogen has a total pressure of 1.50 atm. If the partial pressure of
oxygen is 0.875 atm, what is the partial pressure of nitrogen in the mixture?
A. 0.63 atm
B. 0.750 atm
C. 0.875 atm
D. 1.50 atm
E. 2.38 atm
3. A V-shaped molecule with a tetrahedral electron arrangement around the central atom
should have how many lone pairs on the central atom?
A. 0
B. 1
C. 2
D. 3
E. 4
4. If 0.750 L of solution contains 0.400 g of NaCl, calculate the concentration of this solution.
A.
B.
C.
D.
E.
5.13 x 10-3 M
6.84 x 10-3 M
9.13 x 10-3 M
0.533 M
17.5 M
5. Predict the molecular shape of ICl3.
A.
B.
C.
D.
E.
T-shaped
V-shaped
Trigonal bipyramid
Trigonal planar
Tetrahedral
6. Given the exothermic reaction below, what conditions would favor the formation of
ammonia?
N2(g) + 3H2(g)  2NH3(g)
A.
B.
C.
D.
E.
High pressure, high temperature
Low pressure, high temperature
High pressure, low temperature
Low pressure, low temperature
Low pressure, unaffected by temperature
2014 Regional
Chemistry – 2
7. What is the answer to the problem below, reported to the correct number of significant
figures?
3.927 + 6.1
1.792
A. 6
B. 5.6
C. 5.60
D. 5.595
E. 5.5954
8. How many moles of chlorine gas does it take to fill a 2.4 L vessel at a temperature of 20.0 oC
and a pressure of 1.3 atm?
A.
B.
C.
D.
E.
0.065 mol
0.13 mol
0.95 mol
1.0 mol
1.9 mol
9. What is the most electronegative element listed below?
A. As
B. Si
C. Ga
D. P
E. Ge
10. When the reaction below is balanced with the smallest, whole-number coefficients, what is
the coefficient on oxygen?
C3H7OH(g) + O2(g)  CO2(g) + H2O(g)
A.
B.
C.
D.
E.
1
2.5
4.5
5
9
11. What mass of NaOH is needed to prepare 150.0 mL of a 0.185 M solution?
A.
B.
C.
D.
E.
0.0278 g
1.11 g
1.50 g
4.4 g
40.0 g
12. Which molecule below contains the greatest number of π-bonds?
A. O2
B. F2
C. SO
D. N2
E. CH2O
2014 Regional
Chemistry – 3
13. What is the molecular mass of B2H6?
A.
B.
C.
D.
E.
1.008 g/mol
10.81 g/mol
11.82 g/mol
13.83 g/mol
27.67 g/mol
14. Which of the following represents the largest amount of mass?
A.
B.
C.
D.
E.
1.00 x 10-5 kg
0.0100 g
1.00 x 104 µg
1.00 cg
100 mg
15. How many of the following are named correctly?
Compound
MgO
SiO2
NaNO2
N2O4
A.
B.
C.
D.
E.
Name
Manganese(II) oxide
Silicon dioxide
Sodium nitrite
Nitrogen(II) tetroxide
0 (none are named correctly)
1
2
3
4 (all are named correctly)
16. What is the formula of iron(III) sulfide?
A. Fe3S
B. FeS3
C. FeS
D. Fe3S2
E. Fe2S3
17. The mass of an atom is due primarily to ______________; the volume of an atom is due
primarily to __________________, respectively.
A.
B.
C.
D.
E.
Protons; neutrons and electrons
Protons and electrons; neutrons
Electrons; protons and neutrons
Protons and neutrons; electrons
Neutrons; protons and electrons
2014 Regional
Chemistry – 4
18. Which of the following lists the proper charge for each subatomic particle?
A.
B.
C.
D.
E.
Proton = -1; Neutron = 0; Electron = +1
Proton = +1; Neutron = -1; Electron = 0
Proton = 0; Neutron = +1; Electron = -1
Proton = -1; Neutron = +1; Electron = 0
Proton = +1; Neutron = 0; Electron = -1
19. In nuclear chemistry, α-decay involves a nucleus emitting a particle made up of two
neutrons and two protons, leaving the rest of the nucleus behind. If an atom of uranium (U)
undergoes α-decay, what element will be produced?
A. Cm
B. Pu
C. U
D. Th
E. Ra
20. In an oxidation/reduction reaction, the role of a reducing agent is to:
A.
B.
C.
D.
E.
Provide electrons to the oxidizing agent.
Act as a spectator species.
Serve as a passive cathode.
Accept electrons from the oxidizing agent.
Serve as an active cathode.
21. Which species below has the largest radius?
A. Se2-
B. Br -
C. Kr
D. Rb+
E. Cl -
22. Given the balanced reaction below, how many moles of NaOH are required to completely
react with 25.0 g of CO2?
CO2(g) + 2NaOH(aq)  Na2CO3(aq) + H2O(l)
A. 0.284 mol
B. 0.568 mol
C. 1.14 mol
D. 50.0 mol
E. 66.5 mol
23. Which of the following samples contains the greatest number of chlorine atoms?
A.
B.
C.
D.
E.
0.100 mol PbCl4
0.150 mol CHCl3
0.200 mol Cl2
0.250 mol CHF2Cl
0.300 mol C2H7Cl
2014 Regional
Chemistry – 5
24. The mass percents of hydrogen in samples of caffeine from two different sources are
identical. This is an illustration of what fundamental law of chemistry?
A.
B.
C.
D.
E.
The law of definite composition.
The law of conservation of mass.
The law of multiple proportions.
Avogadro’s law.
Dalton’s law.
25. For the reaction below at equilibrium, PH2 = 0.500 atm, PF2 = 0.300 atm, and PHF = 2.50 atm.
What is the value of Kp for this reaction?
H2(g) + F2(g)  2HF(g)
A.
B.
C.
D.
E.
0.375
10.4
16.7
33.3
41.7
26. Which species below contains both ionic and covalent bonds?
A. BaCl2
B. NaNO2
C. HF
D. CO32-
E. TiCl4
27. A gas sample in a 4.30 L container has a pressure of 648 torr. If the volume of the container
is expanded to 6.00 L at constant temperature, what is the new pressure of the gas?
A.
B.
C.
D.
E.
0.611 torr
432 torr
464 torr
648 torr
904 torr
28. Which reaction below shows the properly balanced reaction between sulfur trioxide and
carbon to form sulfur dioxide and carbon dioxide?
A.
B.
C.
D.
E.
2SO3(g) + C(s)  2SO2(g) + CO2(g)
SO3(g) + C(s)  SO2(g) + CO2(g)
2SO3(g) + C(s)  S2O4(g) + CO2(g)
SO3(g) + C(s)  SO2(g) + CO(g)
S(g) + 2O2(g) + C(s)  SO2(g) + CO2(g)
2014 Regional
Chemistry – 6
29. Which of the following reactions is labeled incorrectly?
A.
B.
C.
D.
E.
2C2H6(g) + 7O2(g)  4CO2(g) + 6H2O(g)
CaO(s) + CO2(g)  CaCO3(s)
Mg2+(aq) + 2OH-(aq)  Mg(OH)2(s)
H2SO4(aq) + Ba(OH)2(aq) BaSO4(aq) + 2H2O(l)
All of the above equations are labeled correctly.
Combustion reaction
Decomposition reaction
Precipitation reaction
Acid/base reaction
30. Which of the aqueous solutions below would have the lowest freezing point? Assume all
solutions are ideal.
A.
B.
C.
D.
E.
0.25 m CaCl2
0.25 m sucrose (C12H22O11)
0.25 m glucose (C6H12O6)
0.25 m NaCl
All of the above solutions will have the same freezing point
31. Which of the following has the greatest number of unpaired electrons in its ground-state
configuration?
A. P
B. Sc
C. Ca
D. F
E. B
32. When a reaction absorbs heat, it is considered to be:
A.
B.
C.
D.
E.
Exergonic
Exothermic
Endergonic
Endothermic
Impossible to determine
33. The balanced reaction between compounds A and B is given below. If 20.0 g of compound
A completely reacts with 16.0 g of compound B, with no excess of either reactant left over,
what mass of compound C is produced?
A + 2B  3C
A. 16.0 g
B. 20.0 g
C. 24.0 g
D. 36.0 g
E. 60.0 g
34. Which of the following is a chemical property?
A.
B.
C.
D.
E.
Silver utensils tarnish over time.
Water boils at 100.0 oC.
Dry ice sublimes at room temperature.
A block of wood weighs 1.25 lbs.
A Granny Smith apple is green.
2014 Regional
Chemistry – 7
35. Which of the following is not a valid set of quantum numbers for an electron in a ground
state chromium (Cr) atom?
A.
B.
C.
D.
E.
(1,0,0,+ ½)
(2,1,0,- ½)
(3,2,1,+ ½)
(4,0,0,- ½)
(4,1,-1,+ ½)
36. An 85.0 mL weak monoprotic acid solution is titrated by 0.270 M KOH. It takes 39.85 mL of
the titrant to reach the equivalence point. What is the concentration of the weak acid
solution?
A. 0.0862 M
B. 0.108 M
C. 0.127 M
D. .270 M
E. 10.8 M
37. If a reaction is second order in compound A, third order in compound B, and zero order in all
other species, what is the overall reaction order?
A. 2
B. 2.5
C. 3
D. 4
E. 5
38. What volume will 0.350 moles of fluorine gas occupy at STP?
A.
B.
C.
D.
E.
0.350 L
7.84 L
8.44 L
22.4 L
24.1 L
39. Balance the reaction below.
Al(s) + Cl2(g)  AlCl3(s)
A.
B.
C.
D.
E.
Al(s) + Cl2(g) + Cl(g)  AlCl3(s)
2Al(s) + 3Cl2(g)  2AlCl3(s)
Al(s) + Cl2(g)  AlCl2(s)
Al(s) + 3Cl(g)  AlCl3(s)
Al(s) + Cl2(g)  AlCl3(s)
40. How many milliliters of 0.594 M NaOH are required to completely react with 25.00 mL of
0.350 M H2SO4?
A.
B.
C.
D.
E.
7.37 mL
8.75 mL
14.8 mL
25.0 mL
29.5 mL
2014 Regional