MC Electrochemistry
MULTIPLE CHOICE
1.
Which of the following is true of an electrochemical cell?
a) the cathode is the site of reduction
d) charge is carried from one electrode to
another by metal atoms passing
through sthe solution
e) the cathode is the site of oxidation
b) the anode is negatviely charged
c) the cell voltage is independent of
concentration
ANS:
A
REF:
AP chem 10th ed, Research & Ed Assoc
2.
The standard electrode in electrochemistry involves the oxidation or
reduction of which of the following?
a) gold
b) platinum
c) copper
ANS:
E
3.
d) magnesium
e) hydrogen
REF:
AP chem 10th ed, Research & Ed Assoc
Use the half reactions below to answer the following question:
The anode of this cell is composed of which of the following materials?
a) Zn
b) Cr
c)
ANS:
d)
e) water
A
REF:
AP chem 10th ed, Research & Ed Assoc
4.
One faraday of electricity (one mole of electrons) is passed through each of
the following solutions.
Beaker A contains Hydrogen ions (
Beaker B contains Zinc ions (
)
)
Beaker C contains Silver ions (
Beaker D contains Copper(II) ions (
)
)
Which of the following answers correctly lists the amount of substance formed at one of the
electrodes?
a) 4.002 g of hydrogen
b) 65.54 g of zinc
c) 65.37 g of copper
ANS:
D
REF:
d) 107.86 g of silver
e) 195.1 g of platinum
AP chem 10th ed, Research & Ed Assoc
5.
The approximate mass of aluminum needed to provide a mole of electrons in
an electrolytic cell is
a) 3 g
b) 9 g
c) 18 g
ANS:
d) 27 g
e) 81 g
B
REF:
AP chem 10th ed, Research & Ed Assoc
6.
The reaction below takes place in a cell in which all of the concentrations are
equal to 1.0M.
What will happen to the reaction quotient, Q and the cell potential, E, if the concentration of
is INCREASED?
a) Q and E both increase
b) Q increases, E decreases
c) Q and E both decrease
ANS:
B
REF:
d) Q decreases, E increases
e) Q decreases, E remains the same
AP chem 10th ed, Research & Ed Assoc
7.
Using the list of reduction potentials, determine which of the following
metals is the most difficult to oxidize.
a) Chromium
b) Copper
c) Iron
ANS:
B
8.
d) Lead
e) Manganese
REF:
AP chem 10th ed, Research & Ed Assoc
The equation below refers to a common electrochemical cell.
Which expression gives the value of ?G in kJ/mol for this reaction?
a)
d)
b)
e)
c)
ANS:
C
9.
REF:
MC & FR, Demmin & Hostage
The equation below refers to a common electrochemical cell.
When the equilibrium constant for this reaction is reported in scientific notation, the
exponent for the 10 is closest to
a) -100
b) -50
c) 0
ANS:
E
10.
d) +50
e) +100
REF:
MC & FR, Demmin & Hostage
The equation below refers to a common electrochemical cell.
Which set of non-standard concentrations does NOT produce a voltage for the cell different
from its
value?
a)
d)
b)
e)
c)
ANS:
B
REF:
MC & FR, Demmin & Hostage
11. Zn(s) is used to reduce other compounds in chemical reactions. If a chemist needs a
substance that is more effective in its reducing ability, which of the following species would be the
best choice?
a) Na
b)
ANS:
c)
d)
A
REF:
AP Prac Exam 1023
The following THREE questions refer to galvanic cells made from different combinations of
the three half-cells described below.
Half-cell 1: strip of Al(s) in 1.00 M
Half-cell 2: strip of Cu(s) in 1.00 M
Half-cell 3: strip of Fe(s) in 1.00 M
12.
What is the standard cell potential of galvanic cell Z?
a) 0.26 V
b) 0.78 V
ANS:
c) 2.34 V
d) 3.22 V
B
13.
REF:
AP Prac Exam 1023
In galvanic cells Y and Z, which of the following takes place in half-cell 3 ?
a) Reduction occurs in both cell Y and
cell Z.
b) Oxidation occurs in both cell Y and
cell Z.
ANS:
C
14.
REF:
c) Reduction occurs in cell Y, and
oxidation occurs in cell Z.
d) Oxidation occurs in cell Y, and
reduction occurs in cell Z.
AP Prac Exam 1023
If the half-cell containing 1.00 M
with a half-cell containing 5.00 M
in galvanic cells Y and Z is replaced
, what will be the effect on the cell voltage of the
two galvanic cells?
a) The voltage will increase in both cells. c) The voltage will increase in cell Y and
decrease in cell Z.
b) The voltage will decrease in both cells. d) The voltage will decrease in cell Y and
increase in cell Z.
ANS:
C
REF:
AP Prac Exam 1023
15.
Use the reduction potentials below to determine which one of the reactions
listed is thermodynamically favored.
Reduction Potentials,
-0.403V
-1.18V
+0.521V
+0.771V
a)
b)
c)
ANS:
d)
e)
C
REF:
Pearson Ed Test Prep Series
16.
Magnesium reacts with dilute hydrochloric acid to produce hydrogen gas.
silver does not react in dilute hydrochloric acid. Based on this information, which of the
following reactions will occur as written?
a)
d)
b)
e)
c)
ANS:
C
REF:
Pearson Ed Test Prep Series
Use the following information to answer the next THREE questions
A cell is set up using the following half reactions under standard conditions
E?= -2.37 V
E?= +0.80 V
17.
What is the voltage of the cell made with silver and magnesium?
a) +1.57 V
b) +3.17 V
c) +3.97 V
ANS:
d) -0.77 V
e) +0.77 V
B
REF:
Pearson Ed Test Prep Series
18.
What are the products of the reaction for the cell made with silver and
magnesium?
a)
b)
c)
ANS:
d)
e) No reaction occurs
B
19.
a) no change
REF:
If the
Pearson Ed Test Prep Series
is changed to 0.50 M, what will initially happen to the voltage?
d) drop to zero
b) increase
e) There is not enough information to
make a prediction
c) decrease to a non-zero value
ANS:
B
20.
REF:
Pearson Ed Test Prep Series
According to the half-reaction table below,
E= –0.14 V
E= –1.03 V
which species is the most easily reduced?
a)
b)
ANS:
c)
d)
B
21.
REF:
NCO 2007
Which species can be reduced but cannot be oxidized?
a)
c)
b)
d)
ANS:
D
REF:
NCO 2007
22. The mass of metal deposited by the electrolysis of an aqueous solution of metal ions
increases in direct proportion to which property or properties?
I. Current provided to the cell
II. Time that the current is allowed to run
III. Charge on the metal ion
a) I only
b) III only
ANS:
C
c) I and II only
d) I, II and III
REF:
NCO 2007
23. What is the coefficient for
number coefficients?
+
when the half equation is balanced with the smallest whole
a) 2
b) 4
ANS:
c) 6
d) 8
B
24.
REF:
NCO 2006
Consider a voltaic cell based on these half–cells.
E = +0.80 V
E = –0.40 V
Identify the anode and give the voltage of this cell under standard conditions.
a) Ag;
b) Cd;
ANS:
B
c) Ag;
d) Cd;
= 0.40 V
= 1.20 V
REF:
= 2.00 V
= 2.00 V
NCO Nat'l 1999
25. Which expression gives the value for ?G? in kJ/mol for the reaction shown
below at 25? C?
E? = +0.43 V
a)
c)
b)
d)
ANS:
C
26.
REF:
NCO Nat'l 1999
Which one of the following cannot be reduced during a chemical reaction?
a)
c)
b)
d)
ANS:
A
REF:
NCO 2014
27. Use the E? values in the table below to determine which of the following reactions will give the
highest potential in a voltaic cell.
a)
b)
c)
d)
ANS:
D
REF:
NCO 2014
28. According to the equations and data in the table below, which species is the most easily oxidized
of the following choices?
a)
b)
c)
d)
ANS:
B
REF:
NCO 2014
29. The cell potential for the voltaic cell depicted below is 0.109 V under standard conditions, 1M
Ni2+(aq) and 1 M Pb2+(aq).
Which change will increase the voltage?
a) The 1 M
solution is diluted with
.
A
larger
Ni
electrode
is
used.
b)
c) 50 mL of 1 M NaCl solution is added to precipitatePbCl2.
d) More 1 M Pb2+ solution is added to that half-cell.
ANS:
A
REF:
NCO 2014
30. Aluminum is produced commercially by the electrolysis of Al2O3. How many hours would be
required to produce 250. g of Al using a 5.00 Ampere current?
a)
b)
c)
d)
49.7
149
745
4020
ANS:
B
REF:
31.
When the equation
NCO 2014
is balanced correctly with the smallest whole number coefficients, what is the coefficient for H 2O?
a) 3
b) 5
ANS:
c) 8
d) 10
A
REF:
NCO 2014
32. Zinc is more reactive than copper. In this voltaic cell, which species is reduced
and in which direction do negative ions flow in the salt bridge?
a)
is reduced while negative ions flow from the copper half-cell to the zinc halfcell
b)
is reduced while negative ions flow from the zinc half-cell to the copper halfcell
c)
is reduced while negative ions flow from the copper half-cell to the zinc halfcell
d)
is reduced while negative ions flow from the zinc half-cell to the copper halfcell
ANS:
A
33.
REF:
IB 2014 MC B
What is the cell potential, in V, of the reaction below?
E? = +0.09 V
E? = +0.54 V
a) + 0.63 V
b) + 0.45 V
ANS:
B
34.
c) - 0.36 V
d) + 0.36 V
REF:
IB 2014 MC B
The following standard reduction potentials are given.
E = 0.77 V
E = 1.19 V
What is E for the reaction below?
a) + 0.42 V
b) + 1.96 V
c) - 0.42 V
d) - 1.96 V
ANS:
A
35.
REF:
Chem 13 2014
An experiment was set up as shown.
Half Reaction
(V)
1.36
1.23
- 0.76
- 0.83
Which of the following statements is correct?
a)
b)
c)
d)
The chlorine gas is the anode.
The zinc electrode is the anode.
The platinum electrode is the anode.
There is no anode because there is no salt bridge.
ANS:
B
36.
REF:
New South Wales 2013
An electrochemical cell is set up as shown in the diagram.
Half Reaction
(V)
1.23
0.34
- 0.83
- 1.66
What are two observations for this electrochemical cell?
a) A reading was shown on the voltmeter AND In Beaker 2 the solution became a
darker blue.
b) In Beaker 2 the solution faded AND a reddish precipitate plated onto the copper
electrode.
c) A grey precipitate plated onto the aluminum electrode AND In Beaker 2 the
solution became a darker blue.
d) The voltmeter read zero volts AND a reddish precipitate plated onto the copper
electrode.
ANS:
B
REF:
37.
New South Wales 2005
What factors affect the amount of metal formed during electrolysis?
I. The charge on the metal ion
II. The current
III. The time the electrolysis is allowed to run
a) I and II only
b) I and III only
ANS:
D
c) II and III only
d) I, II and III
REF:
IB 2007
38.
During the electrolysis of acidified water, if 8.4 mL of hydrogen gas is
evolved, what volume of oxygen gas is evolved?
a) 4.2 mL
b) 8.4 mL
ANS:
c) 12.6 mL
d) 16.8 mL
A
39.
REF:
IB 2007
Consider the standard electrode potentials of the following reactions:
Half Reaction
(V)
0.15
0.77
What is the value of the cell potential (in volts) for the spontaneous reaction?
a) +1.69 V
c) +0.92 V
b) +1.39 V
ANS:
d) +0.62 V
D
40.
REF:
IB 2007
Consider the following spontaneous reactions:
Which of the following correctly identifies the species that is most easily oxidized and the
species most easily reduced?
a) Silver solid is the most easily reduced AND Zinc solid is the most easily oxidized.
b) The
ion is the most easily reduced AND zinc solid is the most easily oxidized.
c) The
ion is the most easily reduced AND silver solid is the most easily
oxidized.
d) Zinc solid is the most easily reduced AND the
ion is the most easily oxidized.
ANS:
B
REF:
IB 2007
41.
Aqueous solutions of AgNO3, Cu(NO3)2 and Cr(NO3)3 are electrolyzed using the
same quantity of electricity. How do the number of moles of metal formed compare?
a)
b)
c)
d)
Ag = Cu = Cr
Ag > Cu > Cr
Ag < Cu < Cr
Cu > Ag > Cr
ANS:
B
42.
REF:
IB Unknown year
The standard electrode potentials for two half-cells involving iron are given
below.
= –0.44 V
= +0.77 V
What is the equation and the cell potential for the spontaneous reaction that occurs
when the two half-cells are connected?
a)
= + 1.21 V
b)
= + 0.33 V
c)
= + 0.33 V
d)
= + 1.21 V
ANS:
D
REF:
43.
IB Unknown year
Metallic tin can be produced by the electrolysis of a molten salt containing
ions. Which change(s) would double the amount of tin produced?
I.
Doubling the current passed during electrolysis
II.
Doubling the time used for electrolysis
III.
Using Sn4+ ions instead of Sn2+ ions
a) I only
b) II only
ANS:
C
c) I and II only
d) I, II and III
REF:
44.
IB Unknown year
Consider the following reactions.
= +0.34 V
= –2.36 V
= –0.76 V
Which statement is correct?
a)
will oxidize both
b)
will reduce both
c)
ANS:
and
will oxidize both
d)
will reduce both
A
45.
and
and
and
REF:
IB Unknown year
From the given standard electrode potentials which statement is correct?
= - 2.87 V
= – 0.23 V
= + 0.77 V
a)
can oxidize
b)
can reduce
c)
can oxidize
d)
can reduce
ANS:
C
46.
REF:
IB Unknown year
Given the following standard electrode potentials:
Half Reaction
(V)
2.01
1.23
0.34
- 0.83
Which statement is correct about the electrolysis of copper(II) sulfate solution using graphite
electrodes?
a)
b)
c)
d)
A colorless gas is produced at the anode.
The electrolyte does not change color.
The anode decreases in mass.
A colorless gas is produced at the cathode.
ANS:
D
47.
REF:
IB Unknown year
Given the following standard electrode potentials:
Half Reaction
(V)
2.01
1.23
0.34
- 0.83
A metallic object is electroplated with copper using a solution of copper(II) sulfate. Which statement
is correct?
a) The anode increases in mass.
b) The concentration of
in the solution decreases.
c) Reduction occurs at the anode.
d) The reaction occurring at the cathode is
ANS:
D
REF:
IB Unknown year
48.
Two electrolytic cells are connected in series so that the same current flows
through both cells for the same length of time.
The amount of tin deposited is 0.01 mol. How much copper is deposited?
a) 0.005 mol
b) 0.01 mol
ANS:
B
49.
a)
b)
c)
d)
c) 0.02 mol
d) 0.05 mol
REF:
IB Unknown year
Which statement is correct about the value of
The more positive the value of
The more negative the value of
The more positive the value of
The more negative the value of
ANS:
A
REF:
?
, the greater the driving force for reduction
, the greater the driving force for reduction
, the greater the rate of reaction
, the greater the rate of reaction
IB Unknown year
50. Fuel cells are being developed that use fuels other than hydrogen as their energy
sources. The table below shows four potential fuels and their reactions in the fuel cell. (For
simplicity, symbols of state have been omitted from these reaction equations.)
Fuel Name
methanol
ethanol
ethane
ethane-1,2,diol
Fuel Formula
Reaction in Fuel Cell
Which one of the fuels would produce the greatest amount of CO2 per coulomb of electrical charge
generated?
a) methanol
b) ethanol
ANS:
D
51.
c) ethane
d) ethane-1,2-diol
REF:
Victorian 2008
Four half cells are constructed as follows.
Half cell I: an electrode of metal P in a 1.0 M solution of P+(aq) ions
Half cell II: an electrode of metal Q in a 1.0 M solution of Q+(aq) ions
Half cell III: an electrode of metal R in a 1.0 M solution of R+(aq) ions
Half cell IV: an electrode of Cu(s) metal in a 1.0 M solution of Cu2+(aq) ions
The half cells are connected in pairs, as shown below, to form a series of galvanic cells.
For each cell, the polarity of the electrodes and the voltage generated are recorded.
Half Cells Used
Cathode
Anode
Voltage (V)
I and IV
P
Cu
0.46
II and IV
Cu
Q
0.57
III and IV
Cu
R
1.10
II and III
Q
R
0.53
Which one of the following alternatives lists the metals in order of from most easily oxidized to
least easily oxidized.
a) R, Q, Cu, P
b) Cu, P, Q, R
ANS:
A
52.
c) P, Cu, R, Q
d) P, Cu, Q, R
REF:
Victorian 2008
The following reactions occur spontaneously as written.
Using this information, predict which one of the following pairs of reactants will react
spontaneously.
a)
c)
b)
d)
ANS:
C
53.
REF:
Victorian 2008
Use the following Half reactions to answer the question below.
Half Reaction
(V)
2.87
1.23
- 0.83
- 2.71
When comparing the electrolysis of molten NaF and that of a 1.0 M aqueous solution of NaF,
which one of the following statements is correct?
a) The product at the anodes is the same in both cells and the product at the cathodes is the
same in both cells.
b) The product at the anodes is the same in both cells but the products at the cathodes are
different.
c) The product at the cathodes is the same in both cells but the products at the anodes are
different.
d) The products at the cathodes of the cells are different and also the products at the anodes
are different.
ANS:
D
REF:
Victoria 2008
54. Pain is often felt when a piece of aluminium foil touches an amalgam
filling in a tooth because an electrical current briefly flows. The amalgam contains
tin.The standard electrode potentials are:
= – 1.66 V
= – 0.13V
Which one of the following statements concerning the resulting cell is correct?
a)
b)
c)
d)
Aluminum ions are produced from the foil.
The aluminum foil acts as the cathode.
The emf of the cell is +1.79 V.
Tin ions are discharged into the saliva of the mouth.
ANS:
A
REF:
GCE Adv 2009 Module 4
55.
An aqueous solution of ammonium chloride has a pH less then 7 because
a) the ammonium ions donate protons to water molecules.
b) the chloride ions combine with hydrogen ions to form hydrochloric acid.
c) aqueous ammonium chloride is unstable and evolves ammonia gas leaving
hydrochloric acid.
d) the ammonium ions combine with hydroxide ions to form ammonium
hydroxide leaving an excess of hydrogen ions.
ANS:
A
REF:
GCE Adv 2009 Module 4
Use the following information to answer the next two questions.
Half Reaction
(V)
1.23
0.34
- 0.83
- 0.76
56.
The E?cell for the electrochemical cell above is
a) + 1.10 V
b) + 0.42 V
ANS:
A
c) - 0.42 V
d) - 1.1 V
REF:
Alberta Chem 30 2011
57. Which of the following statements applies to the operation of the
electrochemical cell?
a) A precipitate forms on the Zn(s) electrode.
b) The concentration of
ions decreases.
c) Electrons move through the connecting wires toward the Zn(s) electrode.
d) The
ions move through the salt bridge toward the Zn(s) electrode.
ANS:
D
REF:
Alberta Chem 30 2011
58. Bleach works by reacting with coloured chemicals that cause stains. Common
household bleach contains aqueous sodium hypochlorite, NaOCl(aq), and its production is
represented by the following equilibrium equation.
In the equation above, the species that undergoes disproportionation is
a)
c)
b)
d)
ANS:
A
59.
REF:
Alberta Chem 30 2011
The table below shows the cell potentials for a hydrogen, nickel and an iron half
cell.
Half Reaction
(V)
0.77
0.00
- 0.25
If instead of using hydrogen as the reference, if the
half-reaction is
designated as the reference half-reaction with an electrode potential of 0.00 V, then the
electrical potential for the
half-reaction is
a) + 1.02 V
b) + 0.51 V
ANS:
A
60.
a)
b)
c)
d)
c) - 0.51 V
d) - 1.02 V
REF:
Alberta Chem 30 2011
Which statement is correct for the halogen group?
Halide ions can all be oxidized, with iodide ions being the hardest to oxidize.
Halogen atoms can all be oxidized, with chlorine being the hardest to oxidize.
Chloride ions can be oxidized to chlorine atoms by bromine atoms.
Iodide ions can be oxidized to iodine atoms by chlorine atoms.
ANS:
D
REF:
IB 2007
Use the information below to answer the following two questions
Half Reaction
(V)
+ 0.34
- 0.25
- 0.76
61.
What is the EMF of a galvanic cell made from copper and nickel?
a) + 0.59 V
b) + 0.09 V
ANS:
A
62.
c) - 0.09 V
d) - 0.59 V
REF:
GCE Unit 6 Jun 2007
Which one of the following reactions occurs?
a)
b)
c)
d)
ANS:
D
63.
REF:
GCE Unit 6 Jun 2007
A VCE chemistry student sets up a galvanic cell using two standard half cells with half
reactions.
half cell 1:
half cell 2:
Suitable materials for the electrodes of the two half cells are
a)
b)
c)
d)
half cell 1 = Platinum; half cell 2 = Platinum
half cell 1 = Platinum; half cell 2 = Chromium
half cell 1 = Chromium; half cell 2 = Chromium
half cell 1 = Chromium; half cell 2 = Platinum
ANS:
B
64.
REF:
Victorian 2002
5 L volumes of 1.0 M
, 1.0 M
and 1.0 M
are placed
in three separate electrolytic cells using platinum electrodes. Over a period of 30 minutes, 96,500
coulombs of electric charge are passed through each solution.Which of the following alternatives
correctly indicates the amount, in mole, of metal deposited at the cathode in each cell?
a)
b)
c)
d)
Zero moles of potassium, 1 mole of silver and 2 moles of copper
Zero moles of potassium, 1 mole of silver and 0.5 mole of copper
1 mole of potassium, 1 mole of silver and 0.5 mole of copper
0.5 mole of potassium, 0.5 mole of silver and 1 mole of copper
ANS:
B
REF:
Victorian 2002
65.
Four metals Pb, x, y and z, were connected in pairs and the voltage was recorded.
The results obtained are set out in the table below.
Anode
Pb
y
z
Cathode
x
Pb
Pb
Voltage
0.35 V
1.10 V
2.60 V
What is the order of increasing ease of oxidation of the metals?
a) z, y, Pb, x
b) Pb, x, y, z
ANS:
D
c) x, y, Pb, z
d) x, Pb, y, z
REF:
NSW 2004
Use the information below to answer the following two questions.
A student electrolyses a 1.0 M solution of sodium chloride. Gases are evolved at each
electrode. The reduction table below should be used to help determine the reactions that are
occuring in the cell.
Half Reaction
(V)
1.36
1.23
- 0.83
- 2.71
66.
The gases evolved at the cathode and anode are
a) Anode = oxygen
Cathode = hydrogen
b) Anode = hydrogen
Cathode = oxygen
ANS:
A
REF:
c) Anode = chlorine
Cathode = hydrogen
d) Anode = hydrogen
Cathode = chlorine
Victorian 2003
67.
a)
b)
c)
d)
During this electrolysis, the pH of the solution will
decrease around the cathode and increase around the anode.
increase around the cathode and decrease around the anode.
decrease at both electrodes.
increase at both electrodes.
ANS:
B
REF:
Victorian 2003
68. A student performed three tests to investigate the relative reducing ability of
metals. In each test a metal strip was placed in a solution containing ions of a different
metal. The results are shown in the diagrams.
What is the order of the metals from least likely to be reduced to most likely to be reduced.
a) Z, X, Y
b) X, Z, Y
ANS:
A
69.
copper?
c) Y, X, Z
d) Z, Y, X
REF:
New south Wales 2003
What arrangement of an electrolytic cell would electroplate a silver coin with
a) Cathode = Copper
Anode = Silver Coin
Electrolyte = Copper(II) Sulfate
b) Cathode = Silver Coin
Anode = Copper
Electrolyte = Silver nitrate
ANS:
D
REF:
c) Cathode = Copper
Anode = Silver Coin
Electrolyte = Silver nitrate
d) Cathode = Silver Coin
Anode = Copper
Electrolyte = Copper(II) Sulfate
New South Wales 2002
70. In a galvanic cell in which the following spontaneous reaction takes place, what
process occurs at the cathode?
a) Reduction of
c) Oxidation of
d) Oxidation of
b) Reduction of
ANS:
B
REF:
NCO 2015
71. Which two half reactions, when coupled, will make a galvanic cell that will
produce the largest voltage under standard conditions?
I.
= + 0.34V
II.
= – 0.13 V
III.
= + 0.80 V
IV.
= - 1.66 V
a) I and II
b) I and IV
ANS:
D
c) II and IV
d) III and IV
REF:
NCO 2015
72. An electrolysis cell is operated for 3000 s using a current of 1.50 A. From which
1.0 M solution will the greatest mass of metal be deposited?
a)
b)
ANS:
c)
d)
A
73.
REF:
NCO 2015
Use the data below to calculate
for the reaction
Half Reaction
(V)
1.36
0.95
- 0.13
- 0.83
a) 1.77 V
b) 2.03 V
ANS:
D
c) 0.82 V
d) 1.08 V
REF:
Tro AP Edition (Sterman edited)
74.
Balance the redox reaction equation (occurring in acidic solution) and choose
the correct coefficients for each reactant and product.
a)
b)
ANS:
c)
d)
A
REF:
Tro AP Edition
75.
Use the data below to determine which metal does NOT dissolve in
hydrochloric acid.
Half Reaction
(V)
0.77
0.52
0.15
0.00
- 0.40
- 0.45
- 0.76
a) Zn
b) Cd
ANS:
c) Cu
d) Fe
C
REF:
Tro AP Edition (Sterman edited)
76.
The Zn /
electrode has a standarrd electrode potential of
= - 0.76 V.
How does the relative potential energy of an electron at the Zn /
electrode compare to
the potential enegy of an electron at the standard hydrogen electrode?
a) An electron at the Zn /
has a higher potential energy than an electron at the
standard hydrogen electrode.
b) An electron at the Zn /
has a lower potential energy than an electron at the
standard hydrogen electrode.
c) An electron at the Zn /
has the same potential energy as an electron at the
standard hydrogen electrode.
d) Nothing can be concluded because it is not possible to compare the potential
energies of electrons at different electrode potentials.
ANS:
A
REF:
Tro AP Edition
77.
In an electrochemical cell that is running spontaneously, Q = 0.010 and K =
855. What can you conclude about
a)
is negative and
d) Both potentials are negative, but
B
REF:
?
is positive.
b) Both potentials are postive, but
c) Both potentials are postive, but
ANS:
and
is larger than
is smaller than
is more negative than
Tro AP Edition (Sterman edited)
78.
Which reaction occurs at the cathode of an electrolytic cell containinga
mixture of molten
and
?
a)
c)
b)
d)
ANS:
C
REF:
Tro AP Edition
The next three questions refer to the following passage:
Alcohols are organic compounds containing a hydroxyl (-OH) group. When a solution
containing dichromate ions is added to most alcohols, chromium(III) ions are formed. The
color of the solution changes from bright orange to green.
The unbalanced reaction above shows ethanol reacting with the dichromate ion to produce
acetic acid and the chromium(III) ion. This reaction occurs in acidic solution and is the
chemical reaction used in a breathalyzer that determines a person’s blood alcohol level from
the ethanol vapor present in his or her breath.
A kinetic study was conducted to determine the order of the
ion in the rate law. A
large excess of alcohol and hydrogen ions was used to ensure that their concentrations did
not limit the reaction. The concentration of dichromate was followed
spectrophotometrically, and the absorbance and time values were recorded.
79.
What is the coefficient for water in the balanced redox reaction?
a) 6
b) 11
ANS:
c) 14
d) 19
B
80.
REF:
Kotz, Treichel AP Ed
Which element is oxidized in the reaction?
a) C
b) Cr
ANS:
c) H
d) O
A
REF:
Kotz, Treichel AP Ed
81.
In the kinetic study, the natural logarithms of the absorbance values were
plotted versus time, resulting in a straight line. What does this indicate about the order of
the reaction with respect to the dichromate ion?
a)
b)
c)
d)
The reaction is zero order in dichromate.
The reaction is first order in dichromate.
The reaction is second order in dichromate.
The order cannot be determined from this graph.
ANS:
B
REF:
Kotz, Treichel AP Ed
82.
How many moles of solid chromium can be deposited from a
solution
when a steel wrench is electroplated with a current of 3.00 Amps for 965 seconds?
a)
b)
c)
d)
mol
mol
ANS:
C
REF:
mol
mol
Kotz, Treichel AP Ed
83.
When electricity is passed through molten sodium chloride, solid sodium
metal is formed at the cathode and chlorine gas is formed at the anode. Which of the
following is true regarding this reaction?
a)
b)
c)
d)
?G is positive.
The reaction is at equilibrium.
Electrons travel from the cathode to the anode.
The equilibrium constant has a value greater than 1.
ANS:
A
REF:
Kotz, Treichel AP Ed
The next FOUR questions refer to the following electrochemical cell and
reduction potentials.
Half-reaction
(V)
0.80
- 0.14
- 0.76
84.
Determine the
a) 0.66 V
b) 0.94 V
ANS:
B
85.
a)
b)
c)
d)
c) - 0.94 V
d) 1.74 V
REF:
Kotz, Treichel AP Ed
Which of the following changes would increase the value of
?
Add 50.0 mL of water to each beaker.
Add 0.10 mole of
to the left beaker, producing a precipitate.
Increase the temperature of each solution by 20?C.
Add 1.5 g of
to the left beaker.
ANS:
D
86.
a)
b)
c)
d)
for the voltaic cell pictured above.
REF:
Kotz, Treichel AP Ed
Which of the following is true regarding the salt bridge in this voltaic cell?
Electrons travel through the salt bridge from the cathode to the anode.
Electrons travel through the salt bridge from the anode to the cathode.
Potassium ions travel to the anode, and nitrate ions travel to the cathode.
Potassium ions travel to the cathode, and nitrate ions travel to the anode.
ANS:
D
87.
laboratory?
REF:
Kotz, Treichel AP Ed
If the reverse reaction was desired, how could it be obtained in the
a) Increase the temperature and increase the concentration of the
.
b) Apply an electric potential less than the
for the forward reaction.
c) Apply an electric potential greater than the
for the forward reaction.
d) The reverse reaction is not thermodynamically favored and cannot occur.
ANS:
C
REF:
Kotz, Treichel AP Ed
88.
If the tin electrode was replaced with a strip of zinc, how would the cell
voltage change?
a) Increase
b) Decrease
ANS:
A
c) No Change
d) Become zero
REF:
Kotz, Treichel AP Ed
89.
The overall equation of a voltaic cell is:
= 1.06 V
The standard electrode potential for
, is - 0.26 V. What is the standard
electrode potential for the silver half-cell
a) - 1.32
b) - 0.80
ANS:
, in V?
c) + 0.80
d) + 1.32
C
REF:
IB 2014
90. Which are correct statements about a voltaic cell?
I. A spontaneous redox reaction occurs which converts chemical energy into electrical
energy.
II. Oxidation occurs at the anode.
III. Electricity is conducted by the movement of electrons through the salt bridge.
a) I and II only
b) I and III only
ANS:
A
91.
c) II and III only
d) I, II and III
REF:
IB 2013
The standard electrode potentials of some half-reactions are given below.
Half-reaction
(V)
+ 0.15
+ 0.54
+ 0.77
Which of the following reactions will occur spontaneously?
a) Iodine reduces
b) Iodine reduces
ANS:
D
c) Iodine oxidizes
d) Iodine oxidizes
to
to
REF:
to
to
IB 2013
92. Dilute sulfuric acid is electrolyzed using inert electrodes. What product, and in
what relative amount, is produced at each electrode?
a) Anode = 1 mol
Cathode = 2 mol
b) Anode = 1 mol
Cathode = 2 mol
c) Anode = 2 mol
Cathode = 1 mol
d) Anode = 2 mol
Cathode = 1 mol
ANS:
B
REF:
IB 2008
93. Which pair of metals, when connected in a cell, would give the highest voltage and a
flow of electrons from X to Y?
Half-Reaction
(V)
0.34
- 0.14
- 0.76
- 2.37
a) Metal X = Zinc
Metal Y = Tin
b) Metal X = Tin
Metal Y = Zinc
ANS:
D
94.
c) Metal X = Copper
Metal Y = Magnesium
d) Metal X = Magnesium
Metal Y = Copper
REF:
Scottland 2015
Consider the following information about the reaction of
with various reagents.
(no observed reaction)
(no observed reaction)
And, conisder the following table of reduction potentials:
Half-Reaction
(V)
0.80
0.77
0.34
- 0.25
What is the likely range for the value of
for the half-reaction shown below?
a) Below - 0.23 V
b) Between - 0.44 V and - 0.23 V
ANS:
C
REF:
c) Between 0.77 V and 0.34 V
d) Above 0.77 V
Victorian 2014
Use the following information to answer the next TWO questions
Half-Reaction
(V)
0.80
- 0.76
- 2.92
95.
Which one of the following statements about the cell above is true as the cell
discharges?
a)
b)
c)
d)
The silver electrode is the anode.
The concentration of Zn2+ ions will increase.
The maximum voltage delivered by this cell will be 1.56 V.
Electrons in the external circuit will flow from the silver electrode to the zinc electrode.
ANS:
B
96.
a)
b)
c)
d)
REF:
Victorian 2014
What should be observed at the zinc electrode as the cell discharges?
No change will be observed at this electrode.
The electrode will become thinner and pitted.
Crystals will form over the surface of the electrode.
Bubbles of gas will form over the surface of the electrode.
ANS:
B
REF:
Victorian 2014
97. A diagram of a simple cell is shown. A table of standard reduction potentials is
also provided.
Half-Reaction
(V)
0.80
0.34
Which of the following occurs when the cell is in operation?
a)
b)
c)
d)
Silver ions are formed in solution.
The copper electrode loses electrons.
Electrons travel through the electrolyte in the salt bridge.
The copper electrode increases in mass.
ANS:
B
98.
REF:
NSW 2015
Use the standard reduction table below to answer the following question:
Half Reaction
(V)
1.23
0.53
- 0.83
- 2.92
When an aqueous solution of KI is electrolyzed, whatforms at the anode?
a)
b)
ANS:
c) K
d)
B
99.
REF:
NCO 2016 (Sterman Edited)
In the galvanic cell at standard conditions,
which of the following changes will increase the cell potential?
I. Dilution of the
solution to 0.001 M
II. Dilution of the
solution to 0.001 M
III. Increasing the surface area of the Al(s) electrode
a) I only
b) II only
ANS:
A
c) III only
d) I and III only
REF:
NCO 2016 (Sterman Edited)