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1 | | When the following redox reaction is balanced, the coefficient for S is _____.
HNO3 + H2S ----> NO + S + H2O |
| | A) | 1 |
| | B) | 3 |
| | C) | 4 |
| | D) | 8 |
| | E) | 10 |
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2 | | Which is true about the following balanced redox reaction: 3 CuO(s) + 2 NH3(aq)
----> N2(g) + 3 H2O(l) + 3 Cu(s)? |
| | A) | CuO is the oxidizing agent and Cu is oxidized. |
| | B) | CuO is the reducing agent and Cu is reduced. |
| | C) | CuO is the oxidizing agent and Cu is reduced. |
| | D) | CuO is the reducing agent and Cu is oxidized. |
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3 | | Which component of the following cell is the cathode? K|L||M|N |
| | A) | K |
| | B) | L |
| | C) | M |
| | D) | N |
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4 | | A voltaic cell is prepared using zinc and iron. Its cell notation is as follows:
Zn|Zn2+(1 M)||Fe2+(1 M), Fe3+(1M)|Pt. Which of the following reactions occurs at the cathode? |
| | A) | Fe3+ + e- ----> Fe2+ |
| | B) | Fe2+ ----> Fe3+ + e- |
| | C) | Zn ----> Zn2+ + 2 e- |
| | D) | Zn2+ + 2e- ----> Zn |
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5 | | A cell can be prepared from zinc and iron. What is the Eocell for the cell that forms from the following half reactions? Fe3+ + e- ----> Fe2+, Eo = 0.77 V; Zn2+ + 2e- ----> Zn, Eo = -0.76 V |
| | A) | -1.53 V |
| | B) | -0.01 V |
| | C) | 0.78 V |
| | D) | 0.01 V |
| | E) | 1.53 V |
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6 | | Examine the following half-reactions and select the strongest oxidizing agent among the substances: Sr2+ + 2 e- ----> Sr, Eo = -2.89 V; Cr2+ + 2 e- ----> Cr, Eo = -0.913 V;
Fe2+ + 2 e- ----> Fe, Eo = -0.447 V; Co2+ + 2 e- ----> Co, Eo = -0.28 V. |
| | A) | Cr2+ |
| | B) | Sr2+ |
| | C) | Co2+ |
| | D) | Fe2+ |
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7 | | Calculate the equilibrium constant for the reaction: 2 Cr + 3 Pb2+ ----> 3 Pb + 2 Cr3+ at 25oC. Eocell = 0.61 V. |
| | A) | 4 x 1020 |
| | B) | 8 x 1030 |
| | C) | 9 x 1045 |
| | D) | 3 x 1051 |
| | E) | 8 x 1061 |
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8 | | The equilibrium constant for the reaction of Ni2+ with Cd is 1.17 x 105. Calculate the free energy change for the reaction at 25oC. |
| | A) | -12.6 kJ |
| | B) | -28.9 kJ |
| | C) | 2.43 kJ |
| | D) | 28.9 kJ |
| | E) | 12.6 kJ |
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9 | | What is the potential of the following cell: Cu|Cu2+(0.001 M)||Cu2+(1 M)|Cu?
[Cu2+ + 2e- ----> Cu, Eo = 0.342 V] |
| | A) | -0.253 V |
| | B) | 0.253 V |
| | C) | -0.0887 V |
| | D) | 0.0887 V |
| | E) | None of the above |
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10 | | What mass of copper can be deposited by the passage of 12.0 A for 25.0 min through a solution of copper(II) sulfate? [1 C = 1 A·s; F = 96,500 C] |
| | A) | 5.93 g |
| | B) | 3.95 g |
| | C) | 1.97 g |
| | D) | 11.85 g |
| | E) | 29.6 g |
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11 | | When balancing equations with the ion-electron method: |
| | A) | H2O, H+, and OH- ions are added when using a basic solution. |
| | B) | H2O, OH- ions are added when using an acidic solution. |
| | C) | Only H2O is added when using a basic solution. |
| | D) | None of the above |
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12 | | Separating redox equations is simpler if the equation is separated into oxidation and reduction portions. |
| | A) | True |
| | B) | False |
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13 | | Which of the following does not denote the difference in electrical potential between the anode and cathode? |
| | A) | cell voltage |
| | B) | electromotive force |
| | C) | voltmeter |
| | D) | cell potential |
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14 | | The same electrode may act as either the anode or the cathode depending on the second electrode used in setting up the galvanic cell. |
| | A) | True |
| | B) | False |
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15 | | According to the diagonal rule: |
| | A) | Any species on the left of a particular half-cell reaction reacts spontaneously with a species on the right of any half-cell reaction below the first. |
| | B) | Any species on the left of a particular half-cell reaction reacts spontaneously with a species on the left of any half-cell reaction below the first. |
| | C) | Any species on the left of a particular half-cell reaction will not react spontaneously with a species on the right of any half-cell reaction below the first. |
| | D) | None of the above. |
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