Please note that this quiz uses special characters. Not all browsers display special characters properly. For best results please use Internet Explorer 5.5 or newer or Netscape 6.2 or newer.
|
1 | | Which of the following statements is incorrect?
|
| | A) | In an electrolytic cell, reduction occurs at the anode.
|
| | B) | Aluminum metal would form at the cathode during the electrolysis of molten AlBr3.
|
| | C) | The cathode is labeled "+" in a voltaic cell.
|
| | D) | Oxidation occurs at the anode in a voltaic cell.
|
| | E) | Electrons flow from the anode to the cathode in all electrochemical cells.
|
|
|
2 | | Consider the following notation for an electrochemical cell
Zn|Zn2+ (1M)||Fe2+ (1M), Fe3+ (1M)|Pt
What is the balanced equation for the cell reaction?
|
| | A) | Zn(s) + 2Fe3+(aq) →
2Fe2+(aq) + Zn2+(aq)
|
| | B) | Zn2+(aq) + 2Fe2+(aq) →
Zn(s) + 2Fe3+(aq)
|
| | C) | Zn(s) + 2Fe2+(aq) →
2Fe3+(aq) + Zn2+(aq)
|
| | D) | Zn(s) + Fe3+(aq) →
Fe2+(aq) + Zn2+(aq)
|
| | E) | Zn(s) + Fe2+(aq) →
Fe(s) + Zn2+(aq)
|
|
|
3 | | A voltaic cell is constructed from the following half-cells, linked by a KCl salt bridge:
(a) an Fe electrode in 1.0 M FeCl2 solution
(b) a Ni electrode in 1.0 M Ni(NO3)2 solution
Use the table of standard electrode potentials in your textbook to decide which one of the following statements is correct.
|
| | A) | The Ni electrode is the anode.
|
| | B) | Electrons flow from the iron electrode to the nickel electrode.
|
| | C) | The iron electrode is positively charged.
|
| | D) | The iron electrode will gain mass when current flows.
|
| | E) | The salt bridge conducts electrons through solution.
|
|
|
4 | | Consider the electrochemical cell:
Zn(s) | Zn2+(aq) ||
Br-(aq) | Br2(l) | Pt
Use data from the table of standard electrode potentials in your textbook to calculate the standard potential of this cell, Eºcell.
|
| | A) | 0.31 V
|
| | B) | 1.83 V
|
| | C) | -0.31 V
|
| | D) | 1.30 V
|
| | E) | none of the above
|
|
|
5 | | When combined with a Cu2+/Cu electrode (Eº
= 0.34V), which of the following electrodes will produce the largest standard cell potential?
|
| | A) | M+/M, Eº
= 1.00 V
|
| | B) | M2+/M, Eº
= 0.90 V
|
| | C) | X2/X-, Eº
= 0.95 V
|
| | D) | M2+/M, Eº
= -0.30 V
|
| | E) | M+/M, Eº
= -0.50 V
|
|
|
6 | | Consider the following half-reactions and select the strongest oxidizing agent present:
Sr2+(aq) + 2e- →
Sr(s) E° = -2.89 V
Cr2+(aq) + 2e- →
Cr(s) E° = -0.913 V
Co2+(aq) + 2e- →
Co(s) E° = -0.28 V
|
| | A) | Cr2+(aq)
|
| | B) | Sr2+(aq)
|
| | C) | Co2+(aq)
|
| | D) | Sr(s)
|
| | E) | Co(s)
|
|
|
7 | | Given the following standard reduction potentials in acid solution:
Al3+(aq) + 3e- →
Al(s) E° = -1.66 V
Sn4+(aq) + 2e- →
Sn2+(aq) E° = +0.14 V
I2(s) + 2e- →
2I-(aq) E° = +0.53 V
Which of the following is the strongest reducing agent?
|
| | A) | Al3+(aq)
|
| | B) | Al(s)
|
| | C) | I-(aq)
|
| | D) | I2(s)
|
| | E) | Sn4+(aq)
|
|
|
8 | | A redox reaction that involves the transfer of 3 electrons has a standard cell potential of +0.34 V. Calculate ΔGº for this reaction (F = 96500 C/mol).
|
| | A) | -98 kJ
|
| | B) | -32 kJ
|
| | C) | +98 kJ
|
| | D) | +32 kJ
|
| | E) | -8.3 kJ
|
|
|
9 | | If the equilibrium constant Kc is greater than 1 for a given reaction, predict the signs of ΔGº
and Eº
at the same temperature.
|
| | A) | ΔGº
> 0; Eº
> 0
|
| | B) | ΔGº < 0; Eº < 0
|
| | C) | ΔGº > 0; Eº < 0
|
| | D) | ΔGº < 0; Eº > 0
|
| | E) | Cannot predict – it depends on the temperature.
|
|
|
10 | | A voltaic cell consists of Mn/Mn2+ and Cd/Cd2+ half-cells. At 25º
C the cell potential is +0.768 V when the concentration of Mn2+ ions is 0.500 M. Use the Nernst equation to calculate the Cd2+ concentration. Standard electrode potentials are given below. (F = 96500 C/mol)
Cd2+(aq) + 2e- →
Cd(s) E° = -0.402 V
Mn2+(aq) + 2e- →
Mn(s) E° = -1.182 V
|
| | A) | 0.010 M
|
| | B) | 0.050 M
|
| | C) | 0.20 M
|
| | D) | 0.50 M
|
| | E) | 0.25 M
|
|
|
11 | | Which of the following statements about fuel cells is correct?
|
| | A) | Fuel cells are electrolytic cells used to produce fuels such as H2.
|
| | B) | Fuel cells are galvanic cells used to produce fuels such as H2.
|
| | C) | Fuel cells are secondary cells.
|
| | D) | Fuel cells have similar energy efficiency to electric power stations.
|
| | E) | None of the above statements is correct.
|
|
|
12 | | Which of the following statements about the corrosion of iron is incorrect?
|
| | A) | Moisture is necessary in order for iron to corrode.
|
| | B) | Oxygen acts as an oxidizing agent in iron corrosion.
|
| | C) | Corrosion occurs more rapidly at high pH.
|
| | D) | Corrosion occurs more rapidly in the presence of conducting solutions.
|
| | E) | Corrosion of iron slows down when the iron is in contact with zinc metal.
|
|
|
13 | | Which one of the following reactions must be carried out in an electrolytic cell, rather than a voltaic cell?
|
| | A) | Zn + Cd2+ →
Cd + Zn2+ |
| | B) | Al + 3/2Br2 →
Al3+ + 3Br- |
| | C) | 2Al3+ + 3Fe →
2Al + 3Fe2+ |
| | D) | H2 + I2 →
2H+ + 2I- |
| | E) | 2H2 + O2 →
2H2O
|
|
|
14 | | In an electrolytic cell, how many grams of Cu could be plated out of a CuSO4 solution at a current of 5.00 A for 2.00 min? (F = 96500 C/mol) |
| | A) | 318 g |
| | B) | 0.395 g |
| | C) | 0.329 x
10-3 g |
| | D) | 0.198 g |
| | E) | 5.31 g |
|
|
15 | | How many minutes does it take to plate 0.800 g of silver metal onto a serving tray from an aqueous solution of AgNO3 at a current of 2.50 A? (F = 96500 C/mol)
|
| | A) | < 2 minutes
|
| | B) | 2.38 minutes
|
| | C) | 4.77 minutes
|
| | D) | 9.54 minutes
|
| | E) | 23.8 minutes
|
|