徐老湿留学
CHEM 13 NEWS EXAM 2010
UNIVERSITY OF WATERLOO
DEPARTMENT OF CHEMISTRY
20 MAY 2010
TIME: 75 MINUTES
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徐老湿留学
CHEM 13 NEWS EXAM 2010 - Answers
1
Of the first 18 elements, how many are gases at
25 oC and 100 kPa?
A
less than seven
B
seven
6
C6H12O6(s)  2 C2H5OH(l) + 2 CO2(g), ∆Ho = −72 kJ
Which of the following actions causes an increase in
the value of Kc?
*C eight
2
D
nine
E
more than nine
(i) adding some CO2(g)
(ii) transferring the reaction mixture to a vessel of
larger volume
(iii) increasing the temperature
Which of the following substances has the highest
vapour pressure at 25 oC?
B
(ii) only
B
CH3CH2CH2OH
C
(iii) only
C
LiF
D
(i) and (ii)
*E none of the above
Li
Which of the following compounds has the highest
melting point?
A
7
Given that
Ionic Radii (in pm)
LiF
Li+,
*B ZnO
5
(i) only
CH3OH
E
4
A
A
*D H2CO
3
The reaction below reaches equilibrium in a closed
reaction vessel.
68
F−,
LiCl
Zn2+, 74
O2−, 140
D
NaF
Na+, 97
Cl−, 181
E
NaCl
E o = 0.920 V
Ag+(aq) + e−  Ag(s)
E o = 0.799 V
what is E o for the reaction below?
136
C
2 Hg2+(aq) + 2 e−  Hg22+(aq)
2 Ag+(aq) + Hg22+(aq)  2 Ag(s) + 2 Hg2+(aq)
A
0.121 V
*B −0.121 V
For a given substance, which of the following phase
transitions is the most exothermic?
C
0.678 V
D
−0.678 V
E
0.339 V
A
solid → liquid
B
gas → liquid
C
liquid → gas
Fe2+(aq) + 2 e−  Fe(s)
E o = −0.40 V
D
solid → gas
2 H+(aq) + 2 e−  H2(g)
E o = 0.00 V
*E gas → solid
Br2(l) + 2 e−  2 Br−(aq)
E o = +1.09 V
8
What is the ground state electron configuration of
selenium, Se?
A
B
2
2
6
2
6
2
2
2
6
2
6
10
1s 2s 2p 3s 3p 4s 4p
4
6
1s 2s 2p 3s 3p 3d 4p
*C 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p4
2
2
6
2
6
10
2
6
D
1s 2s 2p 3s 3p 3d 4s 4p
E
1s2 2s2 2p6 3s2 3p6 4s2 4p4 4d10
2 /CHEM 13 NEWS EXAM © 2010 UNIVERSITY OF WATERLOO
Given that
which of the following is the strongest reducing agent
under standard conditions?
A
Fe2+(aq)
B
H+(aq)
C
Br2(l)
D
Br−(aq)
*E H2(g)
徐老湿留学
9
13 Let the energy of the 2s level in a hydrogen atom
be –E. What is the energy of the 3s level?
What is the coefficient of O2 when the following
equation is balanced?
1 C10H8(s) + x O2(g) → y CO2(g) + z H2O(l)
A
1
B
6
C
 23 E
*B
 49 E
C
 32 E
D
 94 E
E
3 E
7
*D 12
E
A
14
10 Which of the following will react appreciably with
water at room temperature and pressure to produce
hydrogen?
14 Natural oils, such as vegetable oil, are converted into
solid, edible fats by a process called
A
*A NaH
B
NH3
C
CH4
D
E
fusion
*B hydrogenation
C
crystallization
HCl
D
flash freezing
H2S
E
saponification
11 Cesium forms a number of compounds with oxygen.
A particular compound is found to be 26.5% oxygen
by mass. What is the formula of this compound?
A
Cs2O
B
Cs2O2
C
CsO2
15 The value for the activation energy of the forward
reaction is represented by which letter in the diagram
below?
Molar masses
(in g/mol)
A
Energy
O, 16.00
Cs, 132.9
C
reactants
E
B
*D CsO3
E
D
CsO4
products
Reaction progress
12 Which of the following is the strongest acid in water?
A
HBr
*A A
B
HOBrO2
B
B
C
HF
C
C
D
HOIO2
D
D
E
E
*E HI
© 2010 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 3
徐老湿留学
16 The heat of combustion of C(s) is −394 kJ/mol and
that of CO(g) is −111 kJ/mol. What is the enthalpy
change for the reaction below?
19 The reaction below comes to equilibrium in a closed
reaction vessel of volume 2.50 L.
2 NO2(g)  2 NO(g) + O2(g)
CO(g) → C(s) + ½ O2(g)
A
At equilibrium, there are 3.0 mol NO, 4.00 mol O2 and
22.0 mol NO2. What is the value of Kc for the reaction
above?
505 kJ
*B 283 kJ
*A 0.0298
C
111 kJ
B
33.6
D
−283 kJ
C
1.83
E
−505 kJ
D
13.4
E
0.218
17 Exactly 850 mL of O2 gas is collected over water at
30.0 oC using the setup below. Given that the
barometric pressure was 98.5 kPa and the vapour
pressure of water is 4.24 kPa at 30 oC, what volume
would the pure O2 gas occupy at 98.5 kPa and 30 oC?
20 Which of the following occurs if a 0.10 mol/L solution
of a weak acid is diluted to 0.010 mol/L at constant
temperature?
*A 813 mL
B
818 mL
C
850 mL
D
882 mL
E
888 mL
O2(g)
B
The hydrogen ion concentration decreases to
0.010 mol/L.
B
The pH decreases.
C
The ionization constant, Ka, decreases.
*D The percentage ionization increases.
water
E
A
The freezing and boiling points are both raised.
*C The freezing is lowered and the boiling point is
raised.
The freezing is raised and the boiling point is
lowered.
E
The boiling and freezing points are not affected.
0 mol/L
*B 3.6×10−9 mol/L
The freezing and boiling points are both lowered.
D
all of the above
21 What is the equilibrium concentration of Ag+ in
solution when 0.50 L of 0.10 mol/L AgNO3(aq) and
0.50 L of 0.20 mol/L NaCl(aq) are mixed? Assume the
temperature is 25 oC.
18 How are the boiling and freezing points of water
affected by the addition of a soluble salt?
A
A
C
9.0×10−10 mol/L
D
1.3×10−5 mol/L
E
0.05 mol/L
For AgCl, Ksp = 1.8×10−10
at 25 oC.
22 In which ionic compound does the cation have the
same number of electrons as the anion?
A
LiF
B
NaCl
C
CaO
*D MgF2
E
4 /CHEM 13 NEWS EXAM © 2010 UNIVERSITY OF WATERLOO
KI
徐老湿留学
23 How many moles of NaOH or HCl should be added to
1.0 L of 0.010 mol L−1 formic acid (HCOOH) solution
to obtain a solution with pH = 3.50? Assume no
change in volume. (Choose the closest value.)
Ka = 1.8×10
−4
C
D
E
5.8×10
5.8×10
−3
mol HCl
3.2×10
−4
mol HCl
mol NaOH
B
1.1×10−2
D
1.3×10−4
E
1.5×10−6
27 A 1.00 mol/L solution of Cu(NO3)2(aq) is electrolyzed
using the setup illustrated below. What is the reaction
occurring at the anode?
+ −
24 For the reaction below, Kc = 6.3×104 at 25 oC.
2 NO(g) + Cl2(g)
2.9×10−1
*C 1.6×10−1
3.6×10−3 mol HCl
−3
A
for HCOOH
*A 3.6×10−3 mol NaOH
B
26 When 0.012 moles of a monoprotic acid is dissolved in
o
water to give 1.0 L of solution at 25 C, the final pH is
1.95. What is Ka for this acid?
 2 NOCl(g)
battery
o
In an experiment, carried out at 25 C, 1.0 mol NO
and 1.0 mol Cl2 are added to an evacuated reaction
vessel of volume 1.0 L and then the vessel is quickly
sealed. What is the equilibrium concentration of NO?
A
Pt(s)
Cu(s)
0.50 mol/L
*B 5.6×10−3 mol/L
−3
Cu(NO3)2(aq)
mol/L
C
2.8×10
D
1.6×10−5 mol/L
A
2+
−
Cu (aq) + 2 e → Cu(s)
E
7.9×10−6 mol/L
B
Cu(s) → Cu2+(aq) + 2 e−
C
2 H2O(l) + 2 e− → H2(g) + 2 OH−(aq)
25 What is the molecular geometry of the BrF3 molecule?
The Br atom is the central atom and all the F atoms
are bonded directly to Br.
A
trigonal planar
B
trigonal bipyramidal
*C T-shaped
*D 2 H2O(l) → O2(g) + 4 H+(aq) + 4 e−
E
Pt(s) → Pt4+(aq) + 4 e−
28 Which of the following forms of radiation has the
longest wavelength?
D
square planar
A
infrared
E
trigonal pyramidal
B
x-ray
*C microwave
D
ultraviolet
E
visible
© 2010 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 5
徐老湿留学
29 In the unbalanced chemical equation below, x, y and
z are coefficients to be determined.
1 Fe2+ + x Br2 → y Fe3+ + z Br −
33 What is the oxidation state of each sulfur atom in the
peroxydisulfate ion, S2O82−? In the structure below,
lone pairs are not shown.
When the equation is properly balanced, what is the
value of z?
O
*A 1
B
2
C
1
D
4
E
1
O
S
O
O
O
2
4
A
−2
B
0
C
+4
2
O
S
O
O
*D +6
30 If the pH of a solution changed from 4.0 to 8.0, what
happened to the hydrogen ion concentration?
A
It increased by a factor of two.
B
It decreased by a factor of two.
C
It increased by a factor of 104.
E
+7
34 A Lewis structure for POCl3 is shown below.
O
*D It decreased by a factor of 104.
E
Cl
It decreased by a factor of 102.
P
Cl
Cl
Which of the following statements is correct?
31 Which of the following compounds displays only
covalent bonding?
A
This is most important Lewis structure for the
POCl3 molecule.
B
The phosphorus atom is sp2-hybridized.
*C HOCN
C
The Cl-P-Cl angles are 90o.
D
NaNO3
D
The oxidation state of phosphorus is +4.
E
KH
*E None of the statements above are true.
A
NH4OH
B
Li2O
32 How many sigma (σ) and pi (π) bonds are there in the
allene molecule, H2CCCH2?
35 What is the maximum number of electrons that can
have a principal quantum number of 4 within one
atom?
*A six σ bonds and two π bonds
A
two
B
two σ bonds and six π bonds
B
four
C
four σ bonds and four π bonds
C
eight
D
eight σ bonds and no π bonds
D
sixteen
E
two σ bonds and six π bonds
*E thirty-two
6 /CHEM 13 NEWS EXAM © 2010 UNIVERSITY OF WATERLOO
徐老湿留学
36 How many unpaired electrons are there in a Mn2+ ion in
its ground electronic state? The atomic number of
manganese is Z = 25.
39
Which of the following would need the smallest
quantity of heat to change the temperature of 5 g by
10°C?
A
0
A
I2(s)
B
2
B
H2O(l)
C
3
*C Au(s)
*D 5
D
He(g)
6
E
Cu(s)
E
37 The skeletal structure below for the CH2CHOCN
molecule is incomplete; additional bonding pairs or
lone pairs must be added. When the structure is
properly completed, how many lone pairs are there in
this molecule?
40 Let HA represent a weak monoprotic acid with
Ka = 1.0×10−5. What is the pH at the equivalence
point in the titration of 50.0 mL of 0.20 mol/L HA(aq)
with 0.20 mol/L NaOH(aq)?
A
H
C
C
H
H
O
C
N
Specific Heat
(in J g−1 °C−1)
0.158
I2(s)
4.18
H2O(l)
Au(s)
0.129
He(g)
5.19
Cu(s)
0.385
5.00
*B 9.00
C
7.00
A
none
D
3.00
B
one
E
11.00
C
two
*D three
E
four
38 When temperature is increased, the rate of a reaction
also increases. This observation is best explained by
A
an increase in the frequency of molecular
collisions
B
a decrease in the activation energy, Ea, for the
reaction
C
an increase in the activation energy, Ea, for the
reaction
D
a decrease in the enthalpy change, ∆H, for the
reaction
*E an increase in the fraction of molecules that have
enough energy to react
© 2010 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 7
徐老湿留学
DATA SHEET
CHEM 13 NEWS EXAM 2010
DETACH CAREFULLY
1
1A
1
H
1.008
3
Li
6.941
11
Na
22.99
19
K
39.10
37
Rb
85.47
55
Cs
132.9
87
Fr
(223)
2
2A
4
Be
9.012
12
Mg
3
4
24.31
3B
4B
22
21
20
Ti
Sc
Ca
40.08 44.96 47.88
38
39
40
Sr
Y
Zr
87.62 88.91 91.22
57-71
72
56
La-Lu
Hf
Ba
178.5
137.3
88 89-103 104
Ra
Ac-Lr
Rf
226
57
La
138.9
89
Ac
227.
58
Ce
140.1
90
Th
232.0
5
5B
23
V
50.94
41
Nb
92.91
73
Ta
180.9
105
Db
59
Pr
140.9
91
Pa
231.0
6
6B
24
Cr
52.00
42
Mo
95.94
74
W
183.9
106
Sg
60
Nd
144.2
92
U
238.0
7
7B
25
Mn
54.94
43
Tc
(98)
75
Re
186.2
107
Bh
61
Pm
(145)
93
Np
237.0
8

26
Fe
55.85
44
Ru
101.1
76
Os
190.2
108
Hs
9
8B
27
Co
58.93
45
Rh
102.9
77
Ir
192.2
109
Mt
10

28
Ni
58.69
46
Pd
106.4
78
Pt
195.1
110
Ds
64
63
62
Gd
Eu
Sm
150.4 152.00 157.3
94
95
96
Pu
Am
Cm
(244) (243) (247)
11
1B
29
Cu
63.55
47
Ag
107.9
79
Au
197.0
111
Sg
65
Tb
158.9
97
Bk
(247)
12
2B
30
Zn
65.38
48
Cd
112.4
80
Hg
200.6
112
Cn
66
Dy
162.5
98
Cf
(251)
13
3A
5
B
10.81
13
Al
26.98
31
Ga
69.72
49
In
114.8
81
Tl
204.4
67
Ho
164.9
99
Es
(252)
14
4A
6
C
12.01
14
Si
28.09
32
Ge
72.59
50
Sn
118.7
82
Pb
207.2
68
Er
167.3
100
Fm
(257)
15
5A
7
N
14.01
15
P
30.97
33
As
74.92
51
Sb
121.8
83
Bi
209.0
69
Tm
168.9
101
Md
(258)
Constants:
Conversion factors:
NA = 6.022  1023 mol1
1 atm = 101.325 kPa = 760 torr
R
=
1
=
8.3145 kPa L K mol
=
8.3145 J K1 mol1
Kw =
F
0.082058 atm L K1 mol1
=
16
6A
8
O
16.00
16
S
32.07
34
Se
78.96
52
Te
127.6
84
Po
(209)
70
Yb
173.0
102
No
(259)
17
7A
9
F
19.00
17
Cl
35.45
35
Br
79.90
53
I
126.9
85
At
(210)
71
Lu
175.0
103
Lr
(260)
= 760 mm Hg
o
0 C = 273.15 K
1
1.0×10−14 (at 298 K)
96 485 C mol−1
Equations:
PV = nRT
k t1/2 = 0.693
pH = pKa + log ( [base] / [acid] )
8 /CHEM 13 NEWS EXAM © 2010 UNIVERSITY OF WATERLOO
x
b  b 2  4ac
2a
18
8A
2
He
4.003
10
Ne
20.18
18
Ar
39.95
36
Kr
83.80
54
Xe
131.3
86
Rn
(222)
徐老湿留学
CHEM 13 NEWS EXAM 2011 - Answers
1
At 25 oC and 100 kPa, most of the known elements are
A
monatomic gases
B
diatomic gases
C
liquids
5
*D metallic solids
E
2
6
H2Te < H2Se < H2S < H2O
C
H2S < H2O < H2Se < H2Te
D
H2O < H2S < H2Se < H2Te
E
H2O < H2Te < H2Se < H2S
CsO2
B
H2O
C
O2
D
H2O2
A
H2O(l)  H2O(g)
B
F(g) + e  F (g)
−
7
NaCl(s)  NaCl(aq)
*D Na(g)  Na+(g) + e−
E
Cr
E
Sb
The following reaction reaches equilibrium in a closed
o
reaction vessel at 200 C.
A
increasing the volume of the container, holding
temperature constant
B
adding some CH4 gas to the system, with volume
and temperature held constant
D
increasing the temperature, holding the pressure
constant
E
removing some CO gas from the system, with
volume and temperature held constant
At a certain temperature, the following equilibrium
constants have been measured.
−
H2O
+
D
*C adding some H2 gas to the system, with volume
and temperature held constant
Which of the following processes is the most
endothermic?
C
Kr
Which of the following actions causes the reaction to
proceed from left to right in order to restore
equilibrium?
*E OF2
4
B
o
In which of the following compounds does oxygen
have the highest oxidation state?
A
Rb
CO(g) + 3 H2(g)  CH4(g) + H2O(g), H =−206 kJ
*B H2S < H2Se < H2Te < H2O
3
A
*C As
non-metallic or semi-metallic solids
Which of the following series lists the compounds in
order of increasing boiling point? (from lowest to
highest)
A
Which of the following atoms has electrons in its
outermost shell arranged in the configuration 4s2 4p3 ?
Assume each atom is in its lowest energy state.
A2(s) + 2 B(g)  2 C(g)
K1 = 36
D(s) + 2 E(g)  C(g)
K2 = 20
What is the equilibrium constant at the same
temperature for the reaction below?
½ A2(s) + B(g) 
−
K (g) + Cl (g)  KCl(s)
A
720
B
1.8
C
0.56
*D 0.30
E
2 /CHEM 13 NEWS EXAM © 2011 UNIVERSITY OF WATERLOO
0.090
D(s) + 2 E(g)
徐老湿留学
8
In a particular solution, [Br− ] = 0.020 mol L−1 and
[CrO42− ] = 0.0030 mol L−1. Finely-divided solid silver
nitrate, AgNO3, is slowly added to the solution. What
is [Br− ] when Ag2CrO4(s) just begins to precipitate?
−8
−1
*A 2.1×10 mol L
9
B
6.0×10−8 mol L−1
C
2.7×10−7 mol L−1
D
5.2×10
E
6.4×10 mol L
−13
Ag2CrO4
AgBr
Ksp
1.9×10−12
5.2×10−13
−1
mol L
−4
MgN
B
Mg2N
Mg2N3
E
MgN2
hydroxide,OH−
B
fluoride, F−
C
chloride, Cl−
D
bromide, Br −
B
CO
C
CN−
D
N22−
2−
13 What is the empirical formula of a compound that is
66.64% carbon, 7.45% hydrogen and 25.91%
nitrogen by mass?
*A C3H4N
10 Which of the following ions has the smallest tendency
to be protonated when dissolved in liquid acetic acid,
CH3COOH(l)?
A
NO+
−1
*C Mg3N2
D
A
*E O2
What is the formula of the stable compound formed
by magnesium and nitrogen?
A
12 Which of the following contains only single bonds?
*E iodide, I−
B
C3H4N2
C
C3H3N
D
C4H4N
E
C4H3N2
14 Let DC=C represent the C=C bond dissociation energy
in ethene, H2C=CH2, and DC−C the C-C bond
dissociation energy in ethane, H3C−CH3. How do
these bond dissociation energies compare?
A
DC=C equals DC−C
B
DC=C is exactly equal to 2 × DC−C
C
DC=C is exactly equal to ½ × DC−C
*D DC=C is greater than DC−C but less than 2 × DC−C
11 X-ray radiation is more energetic than microwave
radiation because
E
A
photons of X-ray radiation travel faster than those
of microwave radiation
B
photons of X-ray radiation are heavier than those
of microwave radiation
DC=C is greater than 2 × DC−C
15 Which of the following bonds is most polar?
A
B−O
*B B-F
*C X-ray radiation has a higher frequency than does
microwave radiation
C
C-O
D
X-ray radiation has a longer wavelength than
does microwave radiation
D
C=O
E
C−F
E
photons of X-ray radiation travel slower than
those of microwave radiation
© 2011 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 3
徐老湿留学
16 Consider the following energy level diagram for the
reaction R → P.
19 For the reaction below, Kc = 1.0×10−20.
2 A(g) + B(g)  C(g)
In an experiment, 1.0 mol each of A, B and C are
placed in an empty 1.0 L container and then the
container is quickly sealed. When equilibrium is
established, which of the following will be true?
Potential
Energy
P
Y
A
X
[A] < [B] < [C]
*B [A] > [B] > [C]
R
Reaction progress
Which of the following statements is false?
*A The conversion of R to P occurs via a two-step
process.
C
[A] = [B] = [C]
D
[A] = [B] < [C]
E
[A] > [B] = [C]
20 What percentage of CH3COOH molecules are ionized
in 1.8×10−5 mol L−1 CH3COOH(aq)?
B
X and Y represent reaction intermediates.
A
1.8%
C
The conversion of R to P is endothermic.
B
4.2%
D
At equilibrium, the rate of conversion of R to P is
equal to the rate of conversion of P to R.
C
42%
E
The rate-limiting step is the conversion of X to Y.
17 A solution in which the bromide concentration is
2.0×10−5 mol L−1 is in equilibrium with solid AgBr and
solid AgI. What is the concentration of iodide ion?
A
−8
−1
2.6×10 mol L
*B 5.8×10−9 mol L−1
C
1.5×10−16 mol L−1
D
−12
7.5×10
E
2.9×10−4 mol L−1
AgBr
AgI
Ksp
5.2×10−13
1.5×10−16
*D 62%
E
almost 100%
21 A technician recorded the following curve during a
titration.
pH
−1
mol L
18 Consider the hydrogen halides HF, HCl, HBr and HI.
Which of the statements about them is true?
A
Ka(CH3COOH) = 1.8×10−5
Volume of reagent added
from burette (in mL)
They are all strong acids.
The curve represents the titration of a
B
They are all weak acids.
A
weak acid by adding strong base
C
The boiling point increases with molar mass.
B
strong acid by adding weak base
D
The bond dissociation energy increases with
molar mass.
C
strong base by adding weak acid
D
strong base by adding strong acid
*E none of above
4 /CHEM 13 NEWS EXAM © 2011 UNIVERSITY OF WATERLOO
*E a weak base by adding strong acid
徐老湿留学
Use the table of standard reduction potentials
given below to answer questions 22 through 25.
o
Half–Reaction
+
−
Ag (aq) + e  Ag(s)
–
E
+0.80 V
–
O2(g) + 2 H2O(l) + 4e  4 OH (aq)
+0.40 V
2 H+(aq) + 2e−  H2(g)
0.0 V
2+
−
Sn (aq) + 2e  Sn(s)
–0.14 V
2+
−
Ni (aq) + 2e  Ni(s)
2+
−
2 H2O(l) + 2e  H2(g) + 2 OH (aq)
Al (aq) + 3e  Al(s)
B
Ag(s)
D
Sn(s)
E
Al3+(aq)
–0.76 V
−
−
Ag+(aq)
*C Zn(s)
–0.41 V
Zn2+(aq) + 2e−  Zn(s)
3+
A
–0.25 V
Fe (aq) + 2e  Fe(s)
−
25 Which of the following reagents would spontaneously
reduce Ni2+(aq) to Ni(s) under standard conditions?
–0.83 V
26 Consider the ions K+, Ca2+, Cl− and S2−. In which
series are the species listed in order of decreasing
radius? (from largest to smallest)
–1.66 V
22 Which of the following is the strongest oxidizing agent
under standard conditions?
+
*A S
2−
−
+
2+
> Cl > K > Ca
B
K+ > Ca2+ > S2− > Cl−
C
S2− > Ca2+ > Cl− > K+
D
Ca2+ > K+ > Cl− > S2−
E
Ca2+ > K+ > S2− > Cl−
*A Ag (aq)
B
Ag(s)
+
C
H (aq)
D
Al(s)
E
Al3+(aq)
23 When Ag+(aq) reacts completely with exactly one
mole of H2(g) under standard conditions, how many
moles of solid Ag are produced?
A
1 mol
*B 2 mol
27 A solution is prepared by completely dissolving a
solid mixture of NaOH and Mg(OH)2 in water. For the
resulting solution, which of the following conditions
must be satisfied?
A
[Na+ ] = [Mg2+ ] = [OH− ]
B
[Na+ ] = [Mg2+ ] = 3 [OH− ]
C
[Na+ ] + [Mg2+ ] = 3 [OH− ]
*D [Na+ ] + 2 [Mg2+ ] = [OH− ]
C
0.5 mol
D
4 mol
E
0.25 mol
E
+
2+
−
[Na ] + [Mg ] = [OH ]
28 What is the minimum volume of water needed to
dissolve completely 1.0 g SrF2?
o
24 What is E for the reaction 2 H2(g) + O2(g) → 2 H2O(l)?
*A 1.23 V
B
0.43 V
C
4.06 V
D
0.43 V
E
2.06 V
*A 9.0 L
B
150 L
C
10.5 L
D
5.6 L
E
2.8 L
Ksp(SrF2) = 2.8×10−9
Sr, 87.62 g mol−1
F, 19.00 g mol−1
© 2011 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 5
徐老湿留学
29 What is the molecular geometry of SF4?
A
T-shaped
B
tetrahedral
32 What is the hybridization of the sulfur atom in the
SO32− ion?
A
sp
B
sp2
3
*C see-saw
*C sp
D
D
sp d
E
sp3d2
E
square planar
square pyramidal
30 In the incomplete equation below, NH3 acts as a
Bronsted-Lowry acid and “X” represents a BronstedLowry base. What is the conjugate base of NH3?
33 The phase diagram for an unidentified substance is
shown below.
liquid
Pressure
NH3 + X → ?
solid
A
X
B
XH+
C
NH4+
*D NH2
3
gas
Temperature
−
Which of the following statements is true?
E
OH−
31 What is the general trend observed for the first
ionization energies of the elements in groups 13
through 17?
A
Ionization energies tend to increase from left to
right in a period, and are approximately constant
in a group.
Ionization energies tend to decrease from left to
right in a period, and increase from top to bottom
in a group.
D
Ionization energies tend to decrease from left to
right in a period, and decrease from top to bottom
in a group.
E
Liquid can be converted to solid by increasing the
pressure at constant temperature.
B
The melting temperature of the solid increases as
pressure increases.
C
Solid cannot be converted into gas without first
being converted to liquid.
*D There is only one combination of temperature and
pressure for which solid, liquid and gas can
coexist.
*B Ionization energies tend to increase from left to
right in a period, and decrease from top to bottom
in a group.
C
A
E
More than one of the statements above are true.
34 When the following equation is balanced using the
smallest whole number coefficients, what is the
coefficient of O2?
NH3 + O2 → NO + H2O
Ionization energies are approximately constant in
a period, and decrease from top to bottom in a
group.
A
2
B
3
C
4
*D 5
E
6 /CHEM 13 NEWS EXAM © 2011 UNIVERSITY OF WATERLOO
6
徐老湿留学
35 What is [CH3COOH] at equilibrium if 0.10 moles of
CH3COOH and 0.15 moles of NaOH are dissolved in
enough water to make 1.0 L of solution at 25 oC? For
−5
o
CH3COOH, Ka = 1.8×10 at 25 C.
A
0 mol L−1
B
−5
C
38 The bond dissociation energies for F2 and Cl2 are
−1
approximately 158 and 242 kJ mol , respectively.
Given that the enthalpy change for the reaction below
−1
is ΔH = −54 kJ mol , what is the bond dissociation
energy for the F-Cl bond?
½ F2(g) + ½ Cl2(g) → FCl(g)
−1
1.8×10 mol L
−10
5.6×10
A
−1
200 kJ mol−1
mol L
−9
*B 254 kJ mol
−1
−1
*D 1.1×10 mol L
E
−3
−1
C
146 kJ mol−1
D
454 kJ mol−1
E
346 kJ mol−1
1.3 × 10 mol L
36 The following diagram is sometimes used to illustrate
the structure of benzene, C6H6.
39
Which of the following has the greatest number of
unpaired electrons in its ground electronic state?
A
Al
B
Cl
*C Ti2+
Which of the statements concerning the structure of
benzene is false?
*A The double bonds oscillate rapidly back and forth
between adjacent pairs of carbon atoms.
B
The H-C-C angles are 120o.
C
The carbon atoms form a flat hexagonal ring.
D
The oxidation state of carbon is −1.
E
The carbon-carbon bonds are all the same length.
D
Zn2+
E
S2−
40 Let HA represent a weak monoprotic acid with
Ka = 1.0×10−5. In an experiment, a 50.0 mL
sample of 0.10 mol L−1 HA(aq) is titrated with
0.10 mol L−1 NaOH(aq). At which point during the
titration are the equilibrium concentrations of H+
and OH− equal?
A
37 A particular substance, X, decomposes such that its
concentration decreases by a factor of two every 35 s.
If the initial concentration of X was 1.0 mol L−1, what is
[X] after exactly 140 s?
A
after the addition of exactly 25.0 mL of NaOH(aq)
*B after the addition of slightly less than 50.0 mL of
NaOH(aq)
C
after the addition of exactly 50.0 mL of NaOH(aq)
D
after the addition of more than 50.0 mL of
NaOH(aq)
E
The equilibrium concentrations of H+ and OH− are
never equal.
−1
0.33 mol L
−1
B
0.13 mol L
C
0.25 mol L
−1
−1
*D 0.063 mol L
E
−1
0.67 mol L
© 2011 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 7
徐老湿留学
CHEM 13 NEWS EXAM 2012
UNIVERSITY OF WATERLOO
DEPARTMENT OF CHEMISTRY
10 MAY 2012
TIME: 75 MINUTES
This exam is being written by several thousand students. Please be sure that you follow the instructions below.
We'll send your teacher a report on your performance. Top performers are eligible for a prize.
The names of the top 200 students will be published in the September issue of Chem 13 News.
1. Print your name here:
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RESPONSE sheet.
3. Select, and enter on the STUDENT RESPONSE
sheet, one of the following CODE numbers:
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in a nonsemestered school
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in a semestered school
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Code 4
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Code 5
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student
Code 6
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Code 7
Code 8
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student
Code 9 New Brunswick, Newfoundland, Nova Scotia,
or Prince Edward Island high school student
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4. Print your name (last name, first name and optional
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Also fill in the corresponding circles below your printed
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5. Carefully detach the last page. It is the datasheet.
6. Now answer the exam questions. Questions are not in
order of difficulty. Indicate your choice on the
STUDENT RESPONSE sheet by marking one letter
beside the question number.
• Mark only one answer for each question.
• Questions are all of the same value.
• There is a penalty (1/4 off) for each incorrect
answer, but no penalty if you do not answer.
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Be careful that any erasures are complete—make the
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Code 11 High school student outside Canada
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Carefully detach the last page.
It is the Data Sheet.
徐老湿留学
CHEM 13 NEWS EXAM 2012 - Answers
1
Which statement about the properties of water is
incorrect?
5
6
2
6
10
2
5
2
2
6
2
6
2
5
2
2
6
2
6
2
5
10
2
2
6
2
6
2
6
2
2
2
6
2
6
10
*A 1s 2s 2p 3s 3p 3d 4s 4p
B
The density of water is greater than that of ice.
B
1s 2s 2p 3s 3p 4s 4p
C
1s 2s 2p 3s 3p 4s 4p 4d
D
1s 2s 2p 3s 3p 4s 4p 5s 5p
E
1s 2s 2p 3s 3p 3d 4s 4p
D
Water molecules are V-shaped (bent).
E
Water has the highest boiling point of all the
group 16 hydrides.
Which of the following statements accounts for the
observation that, at 300 K and 10 atm, the molar
volume of C2H6(g) is less than that of H2(g)?
1
5
6
The following exothermic reaction reaches equilibrium
in a closed reaction vessel.
4 HF(aq) + CoO2(s)
 F2(g) + 2 H2O(l) + Co2+(aq) + 2 F −(aq)
Which of the following actions causes net reaction
from left to right?
A
C2H6 molecules are smaller than H2 molecules.
B
The average kinetic energy of H2 molecules is
greater than that of C2H6 molecules.
*A adding something that reacts with Co (aq)
C
The average kinetic energy of H2 molecules is
less than that of C2H6 molecules.
B
increasing the temperature
D
The intermolecular attractions in C2H6(g) are
weaker than they are in H2(g).
C
adding some soluble fluoride salt, such as NaF(s)
D
adding a catalyst
*E The intermolecular attractions in C2H6(g) are
stronger than they are in H2(g).
E
decreasing the volume of the reaction vessel
In which compound does manganese have the lowest
oxidation state?
A
2+
7
MnO2
Given the following reactions and equilibrium
constants
K1
4 Cu(s) + O2(g)  2 Cu2O(s)
*B MnI2
4
2
Water expands as it freezes.
6
3
2
A
*C Water is a good solvent for hydrocarbons of high
molecular weight.
2
What is the electron configuration of bromine (Br) in its
lowest energy state?
C
K2MnO4
D
Mn2O7
E
KMnO4
2 CuO(s)  Cu2O(s) +
2 Cu(s) + O2(g)  2 CuO(s)
+
1.8 × 10
−3
−3
*B 3.6 × 10
C
D
E
O2(g)
what is K for the reaction shown below?
How many moles of K ions are there in 0.12 L of
−1
0.015 mol L K2SO4(aq)?
A
1
2
−3
7.2 × 10
−3
9.4 × 10
−3
5.4 × 10
mol
mol
mol
A
K = K1 K 2
B
K=
K1 K 2
*C K =
K1 K 2
D
K=
K 2 K1
E
K = K1 K 2
mol
mol
2 /CHEM 13 NEWS EXAM © 2012 UNIVERSITY OF WATERLOO
K2
徐老湿留学
8
Which of the following has three unpaired electrons
in its lowest energy state?
A
Li
B
B
A
60
C
Sc
B
90
*D V
E
9
12 In the SOCl2 molecule, the S atom is the central atom
and O and Cl atoms are bonded directly to S. What is
the Cl-S-Cl angle in the SOCl2 molecule? (Choose the
closest value.)
o
o
o
*C 109
Ni
What is the formula of the stable compound formed
by calcium and chlorine?
o
D
120
E
180
o
A
CaCl
B
Ca2Cl
C
Ca3Cl
A
VO
D
CaCl3
B
VO2
13 An oxide of vanadium is 48.5% oxygen by mass.
What is the empirical formula of this oxide?
*E CaCl2
*C VO3
10 What is the net ionic equation for the reaction that
occurs when aqueous solutions of HOCl, a weak acid,
and calcium hydroxide, Ca(OH)2, are combined?
A
2 HOCl(aq) + Ca(OH)2(aq)
−
H (aq) + OH (aq) → H2O(l)
C
2 HOCl(aq) + Ca (aq) + 2 OH (aq)
+
−
2+
−
*D HOCl(aq) + OH (aq) → OCl (aq) + H2O(l)
E
+
−
2+
−
2 H (aq) + 2 OCl (aq) + Ca (aq) + 2 OH (aq)
→ Ca(OCl)2(aq) + 2 H2O(l)
11 The volume of Earth’s oceans has been estimated to
9
3
be about 1 billion cubic kilometres (1×10 km ). About
how many water molecules are there in Earth’s
oceans? (Choose the closest answer.)
A
E
V2O5
*A Fe(s)
→ Ca(OCl)2(s) + 2 H2O(l)
−
V2O3
14 When 0.100 kg of solid metal at 95.0 °C is placed into
0.300 kg of water at 25.0 °C, the final temperature of
the system is 27.4 °C. What is the identity of the
metal? Assume the system is thermally insulated
from its surroundings.
→ Ca(OCl)2(aq) + 2 H2O(l)
B
D
B
Sn(s)
C
Mn(s)
D
Ti(s)
E
Pb(s)
15 Which of the following is not an ionic compound?
A
ammonium fluoride, NH4F
B
sodium hydroxide, NaOH
65
C
lithium nitrate, LiNO3
85
*D oxygen difluoride, OF2
35
10
45
*B 10
C
10
D
10
E
10
100
For water:
3
d = 1 g/mL = 1000 kg/m
Molar mass, 18 g/mol
Specific heat
−1 −1
(in J °C g ):
H2O(l) 4.18
Mn(s)
0.479
Sn(s)
0.228
Fe(s)
0.445
Ti(s)
0.522
Pb(s)
0.130
E
potassium hydride, KH
© 2012 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 3
徐老湿留学
16 Consider the following energy level diagram for a
reaction that occurs in a single step.
Potential
Energy
18 Which of the following substances are produced
when K2O is added to water?
Products
+
A
H2(g), K (aq) and O2(g) only
B
H2(g), K(s) and O2(g) only
C
K (aq) and H2O(l) only
+
−
+
*D K (aq) and OH (aq) only
Reactants
E
Reaction progress
+
K (aq), H2O(l) and O2(g) only
Which of the following statements is true?
−11
19 For the reaction below, Kc = 4.5×10
A
The activation energy for the reverse reaction is
less than zero.
B
Starting from reactants only, and before
equilibrium is established, the rate of the forward
reaction continually increases.
A(g) + 2 B(g)
E
 C(g)
In an experiment, 1.0 mol each of A and C are placed
in an empty 1.0 L container and then the container is
o
sealed and heated to 500 C. Which of the following
statements is true?
*C The effect of a temperature change on the rate is
greater for the forward reaction than for the
reverse reaction.
D
o
at 500 C.
*A The equilibrium concentrations of A and B will
−1
both be very close to 2 mol L .
B
The activation energy for the forward reaction is
less than that of the reverse reaction.
The equilibrium concentration of B will be much
−1
less than 1.0 mol L .
C
The enthalpy change for the forward reaction is
less than zero.
The equilibrium concentration of C will be slightly
−1
greater than 1.0 mol L .
D
The equilibrium concentration of C will be much
−1
greater than 1 mol L .
E
The reaction cannot reach equilibrium from the
specified initial conditions.
17 Suppose that conversion of reactant R to product P
involves the following sequence of reversible
reactions. When the system reaches a state of
dynamic equilibrium, which of the following
statements is true?
Step 1:
Step 2:

→ Q
←


→ P
Q ←

R
−
20 The acetate ion, CH3COO , is the conjugate base of
−5
acetic acid, CH3COOH, a weak acid with Ka = 1.8×10
o
at 25 C. Which of the following statements about the
acetate ion is incorrect?
−
A
The rate of step R → Q is equal to the rate of
step Q → P.
B
[R] = [Q] = [P]
C
[Q] = [P] / [R]
*C The CH3COO ion is a strong base in water.
D
The rate of step Q → R is equal to the rate of
step Q → P.
D
The O-C-O angle in the CH3COO ion is very
o
close to 120 .
E
The C-C-O angle in the CH3COO ion is very
o
close to 120 .
*E The rate of step R → Q is equal to the rate of
step Q → R.
4 /CHEM 13 NEWS EXAM © 2012 UNIVERSITY OF WATERLOO
A
The H-C-H angles in the CH3COO ion are very
o
close to 109 .
B
The negative charge of the CH3COO ion is
shared equally by the two oxygen atoms.
−
−
−
−
徐老湿留学
21 All but one of the following molecules are isomers.
Which one is not an isomer of the others?
23 In which of the following is the nitrogen-to-nitrogen
distance the greatest?
H2C
CH
A
the dinitrogen molecule, N2
H2C
CH
B
the linear azide ion, N3
A
−
*C the hydrazine molecule, N2H4
*B
CH2
D
the diazene molecule, N2H2
C
E
the nitrous oxide molecule, NNO
H3C
CH3
24 In an experiment, the rate of the chemical reaction
between substances X and Y is found to obey the
following equation, where k is a constant.
HC
C
2
CH
rate = k [X] [Y]
CH3
What is the effect on the rate if, in a subsequent
experiment, the starting concentrations of X and Y are
each reduced by a factor of two?
HC
H3C
D
C
C
CH3
A
The rate increases by a factor of four.
B
The rate decreases by a factor of four.
C
The rate increases by a factor of eight.
*D The rate decreases by a factor of eight.
H2C
E
CH
CH
E
CH2
The rate decreases by a factor of two.
25 To determine the percentage by mass of chlorine in a
solid mixture of salts, what action should be
performed first?
22 Which of the following, in principle, spontaneously
oxidizes Zn(s) under standard conditions?
Half–Reaction
3+
−
2+
Fe (aq) + e  Fe (aq)
–
–
I2(s) + 2e  2 I (aq)
+
−
2+
−
2 H (aq) + 2e  H2(g)
Zn (aq) + 2e  Zn(s)
−
3+
Al (aq) + 3e  Al(s)
A
H2(g)
*B I2(s)
o
E
+0.77 V
*A Weigh the salt mixture.
B
Use an oxidizing agent to liberate the chlorine.
C
Add aqueous silver nitrate to the salt mixture.
D
Dissolve the salt mixture in water.
E
Use a reducing agent to liberate the chlorine.
+0.54 V
0.0 V
−0.76 V
–1.66 V
26 Which of the following has the largest radius?
A
Na
*B K
3+
C
Al (aq)
C
Ca
D
Al(s)
D
Cl
E
2+
E
Br
Fe (aq)
© 2012 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 5
徐老湿留学
27 For a given substance, which of the following phase
transitions is the most exothermic?
31 Which of following has the smallest first ionization
energy?
A
solid → liquid
A
nitrogen, N
B
gas → liquid
B
fluorine, F
C
liquid → gas
*C silicon, Si
D
solid → gas
D
phosphorus, P
*E gas → solid
E
chlorine, Cl
32 Which statement about catalysts is incorrect?
28 A cylinder of unknown volume contains helium gas,
He(g), at 3.50 atm and 315 K. The helium gas is then
transferred to a 7.0 L gas cylinder containing Ne(g), at
2.50 atm and 315 K. If the final total pressure at
315 K is 5.75 atm, then what is the volume of the
cylinder that initially contained the helium gas?
(Choose the closest value.)
*A 6.5 L
B
5.0 L
C
9.8 L
D
3.5 L
E
8.2 L
A
A catalyst speeds up both the forward and
reverse reactions.
B
A catalyst is not consumed by a reaction, though
it may be temporarily changed.
C
Catalysts, reactants, and products can be either a
homogeneous or heterogeneous system.
*D A catalyst decreases the enthalpy change of the
reaction it catalyzes.
E
33 Which of the following molecules has at least one
o
bond angle of 120 ?
2−
29 What is the shape of the SO4
A
A catalyst changes the reaction mechanism of the
reaction it catalyzes.
A
C2H2
B
SF6
C
NH3
D
BeF2
ion?
T-shaped
*B tetrahedral
C
see-saw
D
square planar
E
octahedral
*E PF5
−12
o
30 For Mg(OH)2, Ksp = 7.1×10 at 25 C. What is the pH
o
of a saturated solution of Mg(OH)2 at 25 C?
A
3.99
B
3.68
C
7.03
D
10.01
34 When the following equation is balanced and written
with the smallest whole number coefficients, what is
the coefficient of O2?
C5H10O5 + O2 → CO2 + H2O
A
2
B
3
*C 5
*E 10.38
6 /CHEM 13 NEWS EXAM © 2012 UNIVERSITY OF WATERLOO
D
6
E
none of the above
徐老湿留学
35 A 0.250 g sample of an unknown acid requires
−1
17.3 mL of 0.140 mol L NaOH(aq) for complete
neutralization. What is the molar mass of the acid?
Assume the acid has only one acidic hydrogen atom.
−1
A
69.2 g mol
B
137 g mol
C
14.5 g mol
D
242 g mol
−1
38 For the following reactions, the given enthalpy
changes are expressed per mole of product formed.
−1
2 C(s) + 3 H2(g) → C2H6(g),
∆H ° = −84.68 kJ mol
C2H6(g) +
*E 103 g mol
A
36 Of the following structures, which one is the most
important structure for neutral N2O?
*B
N
C
N
D
N
N
N
−1
∆H ° = −393.5 kJ mol
−1
Given the thermochemical equations above, what is
the standard enthalpy change for the reaction below?
The answers are expressed in kJ per mole of C2H6.
−1
N
∆H ° = −241.8 kJ mol
C(s) + O2(g) → CO2(g),
−1
A
−1
O2(g) → H2O(g),
1
2
H2(g) +
7
2
O2(g) → 2 CO2(g) + 3 H2O(g)
−1
−985.3 kJ mol
−1
*B −1428 kJ mol
O
−1
C
−720.0 kJ mol
D
−866.2 kJ mol
E
−550.6 kJ mol
O
−1
−1
O
3−
N
N
39 The ionization of H3PO4 to PO4 involves three
separate ionization reactions. The corresponding
ionization constants are Ka1, Ka2 and Ka3, respectively.
−1
In 1 mol L H3PO4(aq), the equilibrium concentration,
in moles per litre, of one of the species in solution is
approximately equal to Ka2. Which species has an
equilibrium concentration approximately equal to
−8
−1
6.2×10 mol L ?
O
O
E
N
N
37 Formic acid (HCOOH) is a weak monoprotic acid with
−4
Ka = 1.8×10 at 298 K. A solution is prepared by
dissolving 0.010 moles of HCOOH in water to make
1.0 L of solution at 298 K. Which of the following
actions, considered independently, causes an increase
in both the pH of the solution and the percentage
ionization of HCOOH?
(i) diluting with water to a final volume of 2.0 L
(ii) adding 0.004 moles of sodium formate, NaHCOO
(iii) adding 0.004 moles of HCl
*A (i) only
B
(ii) only
C
(iii) only
D
both (i) and (ii)
E
both (ii) and (iii)
+
A
H
B
H3PO4
C
H2PO4
−
For H3PO4,
−3
Ka1 = 6.9×10
−8
Ka2 = 6.2×10
−13
Ka3 = 4.8×10
2−
*D HPO4
E
3−
PO4
40 The strengths of acids are sometimes compared in
terms of their pKa values, where pKa = −log10 Ka.
Which of the following acids would have the largest
value for pKa?
A
hydrochloric acid, HCl(aq)
B
hydrobromic acid, HBr(aq)
C
hydroiodic acid, HI(aq)
D
hypochlorous acid, HOCl(aq)
*E hypobromous acid, HOBr(aq)
© 2012 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 7
徐老湿留学
DATA SHEET
CHEM 13 NEWS EXAM
DETACH CAREFULLY
1
1A
1
H
1.008
3
Li
6.941
11
Na
22.99
19
K
39.10
37
Rb
85.47
55
Cs
132.9
87
Fr
(223)
2
2A
4
Be
9.012
12
Mg
24.31
20
Ca
40.08
38
Sr
87.62
56
Ba
137.3
88
Ra
226
3
4
3B
4B
21
22
Sc
Ti
44.96 47.88
39
40
Y
Zr
88.91 91.22
57-71
72
La-Lu
Hf
178.5
89-103 104
Ac-Lr
Rf
57
La
138.9
89
Ac
227.
58
Ce
140.1
90
Th
232.0
5
5B
23
V
50.94
41
Nb
92.91
73
Ta
180.9
105
Db
59
Pr
140.9
91
Pa
231.0
6
6B
24
Cr
52.00
42
Mo
95.94
74
W
183.9
106
Sg
60
Nd
144.2
92
U
238.0
7
7B
25
Mn
54.94
43
Tc
(98)
75
Re
186.2
107
Bh
61
Pm
(145)
93
Np
237.0
Constants:
NA =
R
6.022×10 mol−1
23
10
→
28
Ni
58.69
46
Pd
106.4
78
Pt
195.1
110
Ds
62
63
64
Sm
Eu
Gd
150.4 152.00 157.3
94
95
96
Pu
Am
Cm
(244) (243) (247)
11
1B
29
Cu
63.55
47
Ag
107.9
79
Au
197.0
111
Sg
65
Tb
158.9
97
Bk
(247)
12
2B
30
Zn
65.38
48
Cd
112.4
80
Hg
200.6
112
Cn
66
Dy
162.5
98
Cf
(251)
67
Ho
164.9
99
Es
(252)
68
Er
167.3
100
Fm
(257)
15
5A
7
N
14.01
15
P
30.97
33
As
74.92
51
Sb
121.8
83
Bi
209.0
69
Tm
168.9
101
Md
(258)
16
6A
8
O
16.00
16
S
32.07
34
Se
78.96
52
Te
127.6
84
Po
(209)
70
Yb
173.0
102
No
(259)
17
7A
9
F
19.00
17
Cl
35.45
35
Br
79.90
53
I
126.9
85
At
(210)
71
Lu
175.0
103
Lr
(260)
1 atm = 101.325 kPa = 760 torr = 760 mm Hg
−1
0.082058 atm L K
=
8.3145 kPa L K−1 mol−1
=
8.3145 J K−1 mol−1
−14
Kw =
1.0×10
F
96 485 C mol
Equations:
26
Fe
55.85
44
Ru
101.1
76
Os
190.2
108
Hs
9
8B
27
Co
58.93
45
Rh
102.9
77
Ir
192.2
109
Mt
14
4A
6
C
12.01
14
Si
28.09
32
Ge
72.59
50
Sn
118.7
82
Pb
207.2
Conversion factors:
=
=
8
←
13
3A
5
B
10.81
13
Al
26.98
31
Ga
69.72
49
In
114.8
81
Tl
204.4
−1
o
mol
0 C = 273.15 K
(at 298 K)
−1
PV = nRT
k t1/2 = 0.693
pH = pKa + log ( [base] / [acid] )
8 /CHEM 13 NEWS EXAM © 2012 UNIVERSITY OF WATERLOO
x=
−b ± b 2 − 4ac
2a
18
8A
2
He
4.003
10
Ne
20.18
18
Ar
39.95
36
Kr
83.80
54
Xe
131.3
86
Rn
(222)
徐老湿留学
CHEM 13 NEWS EXAM 2013 - Answers
1
2
Which of the following is most similar in its properties to
element 12?
4
A
element 4
*A NO2F
B
element 10
B
N2O3
C
element 11
C
NH4Cl
D
element 13
D
Mg3N2
*E element 20
E
KNO2
Each of two identical containers holds one mole of
gas, all at the same temperature.
5
SO2
CH4
A
The SO2 gas has a higher pressure.
B
The CH4 gas has a greater density.
C
The SO2 molecules move, on average, faster
than the CH4 molecules.
6
*D Deviations from ideal gas behaviour are smaller
for the CH4 gas.
E
What is Kc for the reaction below?
4 Cu(s) + O2(g)  2 Cu2O(s)
([Cu]
A
K c = [Cu2 O]
B
K c = [Cu] [O 2 ] [Cu2 O]
C
K c = [Cu2 O] ([Cu][O 2 ] )
4
4
[O 2 ]
2
A
solid to liquid
B
liquid to solid
D
gas to solid
E
gas to liquid
Sulfuric acid, H2SO4, is a diprotic acid. At 298 K, Ka1
−2
is much greater than 1, and Ka2 = 1.1×10 . Which of
the following has the highest concentration at
−1
equilibrium at 298 K in 0.10 mol L H2SO4(aq)?
*A H
The average kinetic energy of SO2 molecules is
greater than that of CH4 molecules.
2
To which process does the term sublimation refer?
*C solid to gas
Which of following statements is true?
3
Of the following compounds, which one contains
nitrogen in an oxidation state of +5?
)
7
B
H2SO4
C
HSO4
D
SO4
E
OH
K c = [O 2 ]
*E K c = 1 / [O 2 ]
2 /CHEM 13 NEWS EXAM © 2013 UNIVERSITY OF WATERLOO
−
2−
−
What is the maximum mass of Ca(CN)2 that can be
obtained from 3.52 g of HCN and 1.77 g of Ca(OH)2?
2 HCN(aq) + Ca(OH)2(aq) → Ca(CN)2(aq) + 2 H2O(l)
A
D
+
1.37 g
*B 2.20 g
C
2.66 g
D
5.99 g
E
12.0 g
Molar masses
−1
(in g mol )
27.03
HCN,
Ca(OH)2, 74.10
Ca(CN)2, 92.12
H2O,
18.02
徐老湿留学
8
Which of the following has the same number of
electrons as a water molecule?
A
B
12 The bond angle in O3 is closest to
o
A
60
B
90
C
109
H2S
o
BH3
−
o
*C OH
o
*D 120
D
E
BeH2
E
o
180
2+
Ne
13 What is the formula of magnesium sulfate?
9
Which of the following ions has the smallest ionic
radius?
A
A
MgS
B
MgS2
C
Mg3S2
−
D
MgSO2
−
*E MgSO4
+
K
2+
*B Ca
C
Cl
D
Br
E
P
3−
14 What is the final temperature when 100.0 mL of water
at 90.0 °C and 200.0 mL of water at 10.0 °C are
mixed? (Choose the closest value.)
10 In the reaction
−
CH3NH2 + H2PO4
 CH3NH3+ + HPO42−
−
Assume no heat is lost to the surroundings, and that
the density and specific heat of water are constant.
o
120 C
the H2PO4 ion acts as
A
*A an acid
*B 40 C
B
a base
C
50 C
C
an oxidizing agent
D
70 C
D
a reducing agent
E
80 C
E
a catalyst
o
o
o
o
15 Which of the following has the lowest boiling point?
−1
11 Compared to pure water, a 0.1 mol L
sodium chloride has
solution of
A
HF
*B HCl
A
a higher pH
C
HBr
B
a lower electrical conductivity
D
HI
C
a lower boiling point
E
LiF
*D a lower freezing point
E
a higher vapour pressure
© 2013 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 3
徐老湿留学
16 A substance R can react to form product P1 or product
P2. The reaction profiles for the two reactions are
shown below.
−10
Potential
Energy
P1
−5
A
1.3×10
B
1.8×10
−1
mol L
−10
−10
*C 2.4×10
P2
R
Reaction progress
Compared to the reaction R → P1, the reaction
R → P2 is
+
19 For AgCl, Ksp = 1.8×10 at 298 K. What is [Ag ] at
equilibrium in a solution prepared by completely
dissolving 0.25 moles of AgNO3 and 1.0 mole of
NaCl in 1.0 L of water at 298 K. Assume there is no
change in volume.
−10
D
3.6×10
E
7.2×10
−10
−1
mol L
−1
mol L
−1
mol L
−1
mol L
−8
−1
20 For 1.0×10 mol L HCl(aq), which of the following is
true at equilibrium?
*A slower and less endothermic
A
B
faster and more endothermic
C
slower and more endothermic
D
faster and less endothermic
pH = 8.0
−
E
*B [Cl ] = 1.0×10
faster and highly exothermic
17 The activation energy for the elementary reaction
−1
X → Y is exactly 100 kJ mol and the enthalpy
−1
change is ∆H = −25 kJ mol . What is the
activation energy for the reverse reaction, Y → X?
−1
−1
75 kJ mol
−1
C
−100 kJ mol
D
25 kJ mol
E
−100 kJ mol
−
C
[H ] = [Cl ]
D
[HCl] = 1.0×10
E
[H ] < [Cl ]
+
−1
mol L
−8
−1
mol L
−
21 Which of the following contains only single bonds?
*A 125 kJ mol
B
+
−8
A
HCN
B
H2CCHCH3
C
CH3CHO
*D CH3NH2
−1
E
HNNH
−1
o
18 Which of the following is a product of the reaction
between H2SO4(aq) and NaOH(aq)?
22 In their pure form, at 25 C and 101.3 kPa, most of
the elements are
A
A
H2(g)
B
H (aq)
+
network covalent solids
*B metallic solids
C
molecular solids
D
gases
E
liquids
*C H2O(l)
D
O2(g)
E
SO2(g)
4 /CHEM 13 NEWS EXAM © 2013 UNIVERSITY OF WATERLOO
徐老湿留学
23 Some standard reduction potentials are given below.
E
+0.77 V
–
I2(s) + 2e  2 I (aq)
+
−
2+
−
2 Al(s) +
+0.54 V
2 H (aq) + 2e  H2(g)
1
2
0.0 V
−0.76 V
Zn (aq) + 2e  Zn(s)
−
3+
Al(s) +
o
Half–Reaction
3+
−
2+
Fe (aq) + e  Fe (aq)
–
26 Given:
Al (aq) + 3e  Al(s)
3
2
3
2
O2(g) → Al2O3(s), ∆H = −1676 kJ
What is the enthalpy change for the reaction below?
(Choose the closest value.)
–1.66 V
Which of the following is the strongest reducing agent
under standard conditions?
3+
A
−1830 kJ
B
−2278 kJ
A
Fe
B
I
*C −268 kJ
C
H2
D
−1012 kJ
D
Al
E
−972 kJ
−
3+
*E Zn
B
50.0%
C
53.9%
3
2
O2(g) → Al2O3(s) + 3 Cl2(g)
27 For an electrochemical cell in which the reaction is
2+
2+
Zn(s) + Cu (aq) → Zn (aq) + Cu(s), the voltage is
related to concentration by
24 A mixture of ZnCl2 and CdCl2 weighs 1.000 g.
Treatment with AgNO3(aq) converts all of the
chloride into 1.902 g of AgCl. What is the percent
by mass of ZnCl2 in the original mixture? (Choose
the closest value.)
15.0%
2+
−1
slightly less than 1.0 mol L
B
about 0.50 mol L
*D 62.6%
C
about 0.026 mol L
E
D
between 1.0×10
84.1%
25 Consider the elements in the second period of the
p-block. The first ionization of these elements
decreases steadily from B to Ne
C
increases from B to O, decreases for F, and
then increases for Ne
−1
−1
−3
−1
−1
mol L
*E much less than 1.0×10
B
2+
The cell is set up with 1.0 mol L Cu (aq) and
excess Zn(s) in a volume of 1.00 L and allowed to
2+
run until equilibrium is reached. What is [Cu ] at
equilibrium?
A
increases steadily from B to Ne
2+
E = 1.10 volts – 0.029 volts × log ( [Zn ] / [Cu ] )
Molar masses
−1
(in g mol )
35.45
Cl,
Zn, 65.38
Ag, 107.9
Cd, 112.4
A
∆H = 102.5 kJ
Cl2(g) + O2(g) → ClO2(g),
2 AlCl3(s) +
A
∆H = −704.2 kJ
Cl2(g) → AlCl3(s),
−10
−10
and 1×10
−1
mol L
−1
mol L
28 A flask of volume 2.38 L contains O2 at a partial
pressure of 48.2 kPa and N2 at a partial pressure of
o
37.6 kPa. If the temperature is 27 C, how many
molecules of N2 are present?
22
D
*A 2.16×10
decreases steadily from B to N and increases
steadily from N to Ne
*E increases steadily from B to N, decreases for O
and increases steadily from O to Ne
23
B
2.40×10
C
3.92×10
D
2.19×10
E
2.26×10
23
24
25
© 2013 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 5
徐老湿留学
29 Which of the following is a nonpolar molecule with
one or more polar bonds?
33 When the following equation is balanced and written
with the smallest whole number coefficients, what is
the coefficient of Al?
*A SO3
Fe3O4
B
SO2
A
2
C
H2O
B
3
D
H2O2
C
4
E
NH3
D
6
0.572 mol
B
0.090 mol
0.360 mol
E
0.427 mol
4 HBr(g) + O2(g)
2
14
6d
2
14
5d
[Rn] 7s 6f
B
[Rn] 6s 4f
C
2
E
10
[Rn] 7s 6d
10
7p
10
6p
 2 H2O(g) + 2 Br2(g)
6d
2
14
7d
0.50 mol L
−1
−1
*B 0.10 mol L
−1
C
0.20 mol L
D
0.20 mol L
E
1.00 mol L
−1
−1
adding a catalyst
B
transferring the mixture to a reaction vessel of
larger volume
C
decreasing the external pressure
increasing the temperature
6
35 What is ∆pH, the change in pH, that occurs when
−1
0.10 mL of 6.0 mol L HCl(aq) is added to 20.0 mL of
−1
a solution which is initially 0.12 mol L HCOOH and
−1
0.15 mol L NaHCOO? Choose the closest value.
10
7p
6
10
7p
6
32 The following pairs of solutions are mixed in equal
volumes. Which combination does not produce a
buffer solution?
A
Fe
A
E
7p
14
[Rn] 7s 7f
+
*D removing some Br2(g)
6
6
2
*D [Rn] 7s 5f
Al2O3
Which of the following actions, when applied to a
reaction mixture at equilibrium, will cause net reaction
to the right?
31 Currently, the last element in group 18 is radon, Rn
(Z=86). Based on the building-up principle, what
would be the abbreviated ground-state electron
configuration for the next element in group 18 should
it be discovered or synthesized?
A
→
34 The enthalpy change, ΔH, for the reaction below, is
−276 kJ per mole of O2.
*C 0.143 mol
D
Al
*E 8
−
30 How many moles of Br are in 250.0 mL of a solution
−1
that is 0.148 mol L with respect to NaBr and
−1
0.212 mol L with respect to CaBr2?
A
+
HCOOH and 0.40 mol L
NH3 and 0.10 mol L
−1
−1
HCOOH and 0.40 mol L
NH3 and 1.00 mol L
−1
−1
−1
∆pH = −0.1
B
∆pH = +0.1
*C ∆pH = −0.2
D
∆pH = −1.5
E
∆pH = +1.5
NaOH
HCl
NaHCOO and 0.10 mol L
A
HNO3
NaHCOO
NH4Cl
6 /CHEM 13 NEWS EXAM © 2013 UNIVERSITY OF WATERLOO
For HCOOH,
−4
Ka = 1.8×10
徐老湿留学
−
36 Which of the following species is not linear?
39 What is the conjugate base of OH ?
+
*A O3
A
H
B
HCN
B
H2O
C
C2H2
C
H3O
D
NNO
E
BeH2
*D O
E
+
2−
+
Na
40 Which of the following compounds has the greatest
ionic character?
A
37 Acetic acid, CH3COOH is a weak monoprotic acid
with pKa = 4.74 at 298 K. Which of the following
−1
should be added to 1.0 L of 1.0 mol L CH3COOH to
obtain a solution with pH = 4.74? Assume that the
addition causes no change in volume.
(Note: pKa = −log10 Ka)
−3
IBr
*B CsF
C
HI
D
HF
E
OF2
mol HCl
A
4.2×10
B
1.0 mol NaOH
*C 0.50 mol NaOH
D
0.50 mol NaCH3COO
E
10
−4.74
mol HCl
38 If the reaction W + X  Y + Z is exothermic in the
forward direction, then what is the effect of an
increase in temperature on the forward rate, the
reverse rate and the equilibrium constant?
Forward
Rate
Reverse
Rate
Equilibrium
Constant
A
increases
increases
increases
B
increases
decreases
increases
C
decreases
decreases
decreases
D
decreases
increases
decreases
increases
decreases
*E increases
© 2013 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 7
徐老湿留学
CHEM 13 NEWS EXAM 2014 - Answers
1
Select the correct ending to make the following a true
o
statement. Compared to one litre of water at 25 C, two
o
litres of water at 25 C …
4
A
−6
A
is twice as dense
B
−2
B
is half as dense
C
0
*C has twice the heat capacity
D
+2
D
has half the heat capacity
*E +6
E
has a vapour pressure that is two times greater
5
2
What is the oxidation state of Cr in K2CrO4?
For which of the following is the number of neutrons
equal to the number of electrons?
*A
17
O
−
17
C
18
O
D
18
O
18
O
Na(g) → Na(s)
B
Na(l) → Na(s)
C
Na(g) → Na (g) + e
−
+
−
*D Na (g) → Na (g) + e
+
−
E
6
E
A
+
B
O
Which of the following processes consumes the
greatest quantity of energy per mole of sodium?
+
2+
−
−
Na(g) + e → Na (g)
Which of the following statements about H2SO3, a
diprotic acid, is true?
*A There is just one lone pair on the sulfur atom.
3
Which statement is not correct for the reaction below?
2 NO(g)  N2(g) + O2(g)
B
It is a strong acid.
C
The hydrogen atoms are bonded directly to
the sulfur atom.
A
At equilibrium, the forward and reverse
reactions occur at equal rates.
D
The OSO bond angles are all approximately
120 degrees.
B
Reaction to the left or to the right occurs
spontaneously until the equilibrium state
is reached.
E
The oxidation state of sulfur is +6.
C
Reducing the volume of the system has no effect
on the equilibrium amounts of NO, N2 and O2.
D
7
The equilibrium amounts of NO, N2 and O2
depend on the initial amounts.
2
*E The equilibrium value of [N2 ] [O2 ] / [NO] is the
same at all temperatures.
2 /CHEM 13 NEWS EXAM © 2014 UNIVERSITY OF WATERLOO
What is the shape of the XeF4 molecule?
A
tetrahedral
B
trigonal pyramidal
*C square planar
D
see-saw
E
zig-zag
徐老湿留学
8
o
The density of an ideal gas at 90 C and 94.0 kPa is
2.80 g/L. What is the molar mass of the gas?
A
23 g/mol
B
45 g/mol
12 Which of the following is a network covalent solid (an
extended network of atoms bonded to each other by
covalent bonds)?
A
I2(s)
B
H2O(s)
*C 90 g/mol
*C SiC(s)
9
D
180 g/mol
E
270 g/mol
Which of the following is an ionic compound?
A
D
C10H8(s)
E
CO2(s)
13 Which of the following Bronsted-Lowry acid-base
pairs is incorrect?
HOCN
Base
*B NH4NO2
*A OH
C
D
E
Acid
−
CH3NH2
H3O
−
B
NH2
NH3
C
NH3
NH4
D
CO3
E
HSO3
SiO2
+
PH3
o
o
+
2−
−
−
HCO3
H2SO3
10 What is the pH of pure water at 37 C? At 37 C,
−14
Kw = 2.4×10 .
A
6.90
B
7.10
C
D
14 What is the maximum mass of KBr that can be
obtained from a mixture containing 13.2 grams of
potassium (K) and 22.2 grams of bromine (Br2)?
A
13.2 g
B
22.2 g
7.19
7.00
*E 6.81
*C 33.1 g
D
35.4 g
E
40.2 g
11 What is the percentage by mass of Cr in Cr2O3?
o
A
34.2%
*B 68.4%
C
76.5%
D
86.7%
E
93.2%
15 Diethyl ether, CH3CH2OCH2CH3, is a liquid at 25 C
and 101 kPa. Which of the following contribute to the
attraction amongst molecules in CH3CH2OCH2CH3(l)?
A
dipole-dipole forces only
B
London dispersion forces only
C
hydrogen bonding forces only
*D dipole-dipole and London dispersion forces
E
hydrogen bonding and London dispersion forces
© 2014 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 3
徐老湿留学
16 According to the reaction profile below, what is the
activation energy for the reverse reaction P → R?
19 Which of the following illustrates how the potential
energy (PE) of a proton and an electron depends on
the distance, r, between them?
PE
Potential energy
20 kJ/mol
A
r
30 kJ/mol
25 kJ/mol
P
10 kJ/mol
R
Reaction progress
B
PE
*A 35 kJ/mol
r
B
45 kJ/mol
C
50 kJ/mol
D
−10 kJ/mol
E
C
−45 kJ/mol
PE
r
17 What is the ground electronic state of Mn
2
2
6
2
6
5
2
2
2
6
2
6
3
2
2
2
6
2
6
5
2
2
6
2
6
2
A
1s 2s 2p 3s 3p 3d 4s
B
1s 2s 2p 3s 3p 3d 4s
2+
?
*D
PE
*C 1s 2s 2p 3s 3p 3d
3
D
1s 2s 2p 3s 3p 4s 4p
E
1s 2s 2p 3s 3p 4s 4d
2
2
6
2
6
2
r
3
−1
18 A solution of 0.060 mol L pyridine (a weak base) has
−
−6
−1
[OH ] = 9.1×10 mol L . What is Kb for pyridine?
A
1.5×10
−4
−4
B
3.0×10
C
8.3×10
D
9.1×10
−11
−6
−9
*E 1.4×10
4 /CHEM 13 NEWS EXAM © 2014 UNIVERSITY OF WATERLOO
E
PE
r
徐老湿留学
20 The equilibrium constants for the following reactions
are denoted by K1, K2, and K3, respectively.
HNO2(aq) + H2O(l)  NO2−(aq) + H3O (aq)
K1
2 H2O(l)  H3O (aq) + OH−(aq)
K2
+
+
NH3(aq) + H2O(I)  NH4 (aq) + OH (aq)
+
−
K3
What is the equilibrium constant for the reaction below?
HNO2(aq) + NH3(aq)  NO2−(aq) + NH4 (aq)
+
A
K1 – K2 + K3
B
K1 K3
23 A current of 4.27 amperes passes through an
electrolysis cell containing CuSO4 for exactly two
hours. How many grams of copper are deposited?
Assume the cell operates with 95.1% efficiency.
(Note: 1 ampere = 1 coulomb per second)
A
4.82 g
*B 9.63 g
C
10.1 g
D
10.6 g
E
19.2 g
24 A mixture of N2(g) and Ne(g) has a mass of 2.88 g and
occupies a volume of 2.50 L at 298 K and 105 kPa.
How many moles of N2 are there in this mixture?
*C K1 K3 / K2
D
K1 K2 K3
*A 0.0946 mol
E
K2 / (K1 K3)
B
0.106 mol
C
0.0113 mol
D
0.112 mol
E
1.15 mol
21 Which of these molecules contains at least one
triple bond?
A
oxalic acid, H2C2O4 (HOOCCOOH)
*B cyanogen, C2N2 (NCCN)
25 What is ∆H for the reaction below?
CH4(g) + I2(g) → CH3I(g) + HI(g)
C
allene, C3H4 (H2CCCH2)
D
ethanal, C2H4O (CH3CHO)
A
E
diazene, N2H2 (HNNH)
*B +35 kJ
22 Select the correct ending to make the following a
true statement. A catalyst ...
A
always provides a surface on which
molecules react
B
lowers the energy of the products
C
induces an alternate reaction pathway
with a higher activation energy
D
increases the frequency of collisions
between molecules
−35 kJ
C
−50 kJ
D
+50 kJ
E
−529 kJ
Bond
energies
(in kJ/mol)
H−C, 413
C−I, 230
H−I, 299
I−I, 151
26 How many electrons are needed to fill the 4f subshell
of an atom?
*E is not consumed by the overall reaction although
it may be temporarily changed
A
two
B
six
C
ten
*D fourteen
E
eighteen
© 2014 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 5
徐老湿留学
27 Which of the following bonds is the most polar?
*A H−O
B
C−N
C
H−C
D
E
31 Excess AgCl(s) is added to a dilute aqueous solution
of CaCl2(aq). Some but not all of the added AgCl
dissolves. Which of the following conditions must be
satisfied at equilibrium?
+
2+
+
2+
+
2+
1
3
−
A
[Ag ] = [Ca ] =
O−N
B
[Ag ] + [Ca ] = 3 [Cl ]
O−F
C
[Ag ] + [Ca ] = [Cl ]
+
[Cl ]
−
−
−
2+
*D [Ag ] + 2 [Ca ] = [Cl ]
28 Element 119 has yet to be discovered or synthesized.
However, because of its position in the periodic table,
only one of the following statements about this element
is likely to be incorrect. Which statement is incorrect?
E
2+
[Ca ] =
1
2
−
[Cl ]
32 The following standard reduction potentials are given.
A
The element would be a metal.
3+
*B The element (call it X) would combine with
fluorine to form a compound with formula XF2.
C
The element would be in the s block.
D
The element would react with water to form a
basic solution.
−
Fe + e  Fe
−
+
−
IO3 + 6 H + 5e
B
the group 3 atoms (B to Tl)
N
E
B
3−
3+
3−
and P
B
−0.53 V
C
−2.66 V
D
+5.04 V
E
+1.96 V
3+
and Al
30 Which of the following statements concerning the
−
nitrate ion, NO3 , is incorrect?
A
2+
→ 5 Fe
3+
+ ½ I2 + 3 H2O
33 Propanoic acid, CH3CH2COOH, is a weak acid with
pKa = 4.87 at 298 K. What is the pH at the equivalence
−1
point in the titration of 30.0 mL of 0.200 mol L
−1
propanoic acid with 0.200 mol L NaOH(aq)?
(Note: pKa = −log10 Ka)
*C the group 15 atoms (N to Bi)
D
E ° = 0.77 V
E ° = 1.19 V
*A +0.42 V
29 Which of the following have three unpaired electrons
in their ground electronic states?
the third period atoms (Na to Ar)
+
IO3 + 6 H + 5 Fe
The element would combine with hydrogen to
form an ionic compound.
A
 ½ I2 + 3 H2O
What is E ° for the reaction below?
−
E
2+
A
4.87
B
5.07
C
7.00
o
The ONO bond angles are all 120 .
*B One of the nitrogen-oxygen bonds is shorter than
the other two nitrogen-oxygen bonds.
C
The nitrogen atom has a formal charge of +1.
D
It is the conjugate base of a strong acid.
E
It is nonpolar.
6 /CHEM 13 NEWS EXAM © 2014 UNIVERSITY OF WATERLOO
*D 8.94
E
9.13
徐老湿留学
38 Electronegativity is a measure of
34 Consider the reaction below.
2 NOCl(g)
 2 NO(g) + Cl2(g), ∆H > 0
Which of the following conditions maximize the
amount of Cl2(g) present at equilibrium?
A
low temperature, high pressure
A
the magnitude of the charge of an electron
B
the energy released when an electron is
added to an atom
C
the energy required to remove an electron
from an atom
*B high temperature, low pressure
*D the ability of an atom to draw electron density
towards itself
C
low temperature, low pressure
D
high temperature, high pressure
E
high temperature, pressure has no effect
35 The solubility of MnS in water is 2.3×10
litre. What is Ksp for MnS?
A
B
C
E
−6
grams per
39 In which of the following solutions does the solute
have the highest degree of ionization? The Ka values
−5
−10
for CH3COOH and HCN are 1.8×10 and 4.8×10 ,
respectively.
−31
4.9×10
−1
A
0.10 mol L
B
0.010 mol L
C
0.10 mol L
D
0.010 mol L
−23
2.8×10
−12
5.3×10
*D 7.0×10−16
E
the average repulsive force experienced by a
given electron
HCN
−1
−1
HCN
CH3COOH
−1
CH3COOH
−1
−6
*E 0.0010 mol L
2.3×10
CH3COOH
40 Which property is represented in the graph below?
36 Which of the following is the weakest acid in water?
*A H2S
B
H2Se
C
H2Te
D
HBr
E
HI
37 What is the lightest element that has two 4s electrons
and eight 3d electrons in its lowest energy state?
A
Fe
B
Ar
C
Kr
*D Ni
E
Cu
A
atomic radius
B
electron affinity
C
density
*D first ionization energy
E
atomic volume
© 2014 UNIVERSITY OF WATERLOO CHEM 13 NEWS EXAM / 7