SCH4U Electrochemistry Test

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SCH4U
Test 7: Electrochemistry
Date: December 18, 2018
Name: _______________________
Date:___________________
Knowledge
Application
Thinking &
Inquiry
Communication
TOTAL
/27
/16
/16
/11
/70
Knowledge:
Multiple Choice (K
/27)
Choose the best answer.
1. Which of the following represents a redox reaction?
A. C + O2  CO2
B. H2O + SO2  H2SO3
C. H3O+ +OH-  2H2O
D. NaCl + AgNO3  AgCl + NaNO3
2. The oxidation number of each chromium atom in Cr2O72- is
A. +5
B. +6
C. +7
D. +12
3. List the ions Co2+, Cu2+ and Zn2+ in order from strongest to weakest oxidizing agents.
A. Zn2+ > Co2+ > Cu2+
B. Co2+ > Cu2+ > Zn2+
C. Cu2+ > Zn2+ > Co2+
D. Cu2+ > Co2+ > Zn2+
4. A piece of Cu reacts spontaneously with 1.0M Pd2+ because
A. Cu is a weaker reducing agent than Pd and E° > 0.
B. Cu is a weaker reducing agent than Pd and E° < 0.
C. Cu is a stronger reducing agent than Pd and E° > 0.
D. Cu is a stronger reducing agent than Pd and E° < 0.
5. Which two species will not react spontaneously at standard conditions?
A. Co with Cl2
B. Cu with Ag+
C. Ag with Zn2+
D. Mg with Cr3+
6. When a piece of Ag is placed in 1.0M NiCl2,
A. the [Cl-] increases.
B. the [Ag+] decreases.
C. the [Ni2+] decreases.
D. no change occurs.
7. Which of the following is correct for an electrolytic cell?
8. Which of the following will inhibit the corrosion of iron?
A. high [O2(aq)]
B. wet conditions
C. coating with zinc
D. increasing the temperature
9. The products of the electrolysis of molten MgCl2 using inert electrodes are
A. hydrogen and oxygen.
B. hydrogen and chlorine.
C. magnesium and oxygen.
D. magnesium and chlorine.
10. Consider the following reaction:
Zn (s) + 2H+ (aq)  Zn2+ (aq) + H2(g)
The species being oxidized is
A. H2
B. H+
C. Zn
D. Zn2+
11. When SO42- reacts to form S2O62-, the sulphur atoms
A. lose electrons and are reduced.
B. gain electrons and are reduced.
C. lose electrons and are oxidized.
D. gain electrons and are oxidized.
12. Which of the following is a list of metals in order from strongest to weakest reducing agents?
A. Au > Ni > Rb
B. Ni > Au > Rb
C. Ni > Rb > Au
D. Rb > Ni > Au
13. Consider the following spontaneous reaction:
Mg (s) + 2HCl (aq)  MgCl2 (aq) + H2(g)
Which of the following statement is correct?
A. Mg is a weaker reducing agent than H2
B. Mg is a weaker reducing agent than H+
C. Mg is a stronger reducing agent than H2
D. Mg is a stronger reducing agent than H+
14. Which of the following will not react spontaneously with H2O at standard conditions?
A. F2
B. Ca
C. Na
D. Sn
15. When a piece of Cu is placed in 1.0M AgNO3,
A. the [Ag+] increases.
B. the [Cu2+] increases.
C. the [NO3-] decreases.
D. no change occurs.
16. Which of the following describes an electrochemical cell?
17. Which of the following aqueous solutions should not be used as an electrolyte in an electrolytic cell?
A. 1.0M KOH
B. 1.0M H2SO4
C. 1.0M CuSO4
D. 1.0M C6H12O6
18. When 1.0M Na2SO4 is electrolyzed, the solution near the anode becomes
A. basic and bubbles form.
B. acidic and bubbles form.
C. basic and no bubbles form.
D. acidic and no bubbles form.
19. Which of the following represents a redox reaction?
A. H2 + I2  2HI
B. HCl + NH3  NH4Cl
C. H2O + CO2  H2CO3
D. 2NaI + Pb(NO3)2  PbI2 + 2NaNO3
20. In an experiment, Ag+ reacts spontaneously with Ru but not with Pd. The relative strength of the
metals from strongest to weakest reducing agent is
A. Ag > Ru > Pd
B. Pd > Ag > Ru
C. Ru > Ag > Pd
D. Ru > Pd > Ag
21. A piece of Ag does not react spontaneously with 1.0M Ti2+ because
A. Ag+ is a weaker reducing agent than Ti2+
B. Ag+ is a weaker oxidizing agent than Ti2+
C. Ag+ is a stronger reducing agent than Ti2+
D. Ag+ is a stronger oxidizing agent than Ti2+
23. Which of the following will react spontaneously with Ag2S at standard conditions?
A. Al
B. Au
C. Co
D. Pb
24. When a piece of Cu is placed in 1.0M HNO3,
A. the [H+] increases.
B. the [Cu2+] decreases.
C. the [NO3-] decreases.
D. no change occurs.
25. When MnO2 changes to Mn2O3 in an alkaline battery, manganese atoms
A. lose electrons and are reduced.
B. gain electrons and are reduced.
C. lose electrons and are oxidized.
D. gain electrons and are oxidized.
Application:
1. Balance the following oxidation-reduction equations. All reactions take place in an acidic
solution unless otherwise indicated. (A
/8)
1. AsH3 + ClO3 -  H3AsO4 + Cl2.
2. MnO4 - + H2O2  Mn2+ + O2
3. MnO2 + ClO3-  MnO4 2- + Cl- (basic solution)
4. N2O4 + Br-  NO2 - + BrO3 - (basic solution)
2. Identify what is oxidized and reduced in the following reactions. Then, identify the oxidizing
agent and reducing agent. (A
/8)
A.
Mg
+
2HCl

MgCl2
+
H2
Specie being oxidized __________________
Specie being reduced ____________
Oxidizing Agent _____
Reducing Agent_______
B.
2K
+
I2 
2 KI
Specie being oxidized __________
Specie being reduced _________
Oxidizing Agent _____
Reducing Agent_______
Thinking: (T
/16)
1. Find the following using a voltaic cell with the line notation: Al(s)|Al3+||Pb2+|Pb(s) (T
a. Calculate the Eo for the reaction.
b. Write the balanced overall REDOX equation for the galvanic cell.
/4)
2. For the following voltaic cell: (T
/12)
Fe(s)  1.00 M Fe2+(aq)  1.00 M Cu2+(aq)  Cu(s)
(a). Draw a picture of the cell. Include a salt bridge in your picture.
(b) Write the cell half-reactions.
(b) Label one half-reaction as the oxidation, the other as the reduction.
(c) Label on half-reaction as the cathode, the other the anode.
(d) Label the direction of electron flow, and label one electrode as the cathode and the
other electrode as the anode.
(e) Write the overall cell reaction.
(f) Determine the standard voltage (Eo) for the battery
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