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1 | |
When the following redox reaction is balanced, the coefficient for Cl2 will be _____, and ____ is the reducing agent.
KMnO4(aq) + KCl(aq) + H2SO4(aq) ----> MnSO4(aq) + K2SO4(aq) + H2O(aq) + Cl2(g). |
| | A) | 1; Mn2+ |
| | B) | 3; Cl- |
| | C) | 3; MnO4- |
| | D) | 8; Cl- |
| | E) | 1; MnO4- |
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2 | |
When the skeleton equation Zn + As2O3 ----> AsH3 + Zn2+, a reaction that is carried out in acid solution, is balanced, the coefficient for AsH3 will be ______. |
| | A) | 1 |
| | B) | 2 |
| | C) | 3 |
| | D) | 5 |
| | E) | 8 |
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3 | |
Consider a voltaic cell constructed from a Ag(s) anode in 1.0 M AgNO3 and a Ni(s) cathode in 1.0 M Ni(NO3)2, linked by an external circuit and by a KCl salt bridge. The balanced overall (net) chemical equation for the cell reaction is |
| | A) | 2 Ag(s) + Ni2+(aq) ----> 2 Ag+(aq) + Ni(s) |
| | B) | Ag(s) + Ni(s) ----> Ag+(aq) + Ni2+(aq) |
| | C) | Ag+(aq) + Ni(s) ----> Ag(s) + Ni2+(aq) |
| | D) | 2 Ag+(aq) + Ni(s) ----> Ni2+(aq) + 2 Ag(s) |
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4 | |
Consider a voltaic cell constructed from a Fe electrode in 1.0 M FeCl2 and a Ni electrode in 1.0 M Ni(NO3)2, linked by an external circuit and a KCl salt bridge. Based on the reduction potentials shown, which of the following statements is correct? Fe2+ + 2 e- ----> Fe, Eo = -0.44 V; Ni2+ + 2 e- ----> Ni(s), Eo = -0.25 V |
| | 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. |
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5 | |
Given the following standard reduction potentials in acid solution, the species most likely to be reduced is:
Al3+ + 3 e- ----> Al(s) Eo = -1.66 V;
AgBr(s) + e- ----> Ag(s) + Br- Eo = 0.07 V;
Sn4+ + 2 e- ----> Sn2+ Eo = 0.14 V;
Fe3+ + e- ----> Fe2+ Eo = 0.77 V |
| | A) | Fe3+ |
| | B) | Fe2+ |
| | C) | Br- |
| | D) | Al3+ |
| | E) | Al |
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6 | |
Given the following standard reduction potentials in acid solution, which species is the strongest oxidizing agent?
Al3+ + 3 e- ----> Al Eo = -1.66 V;
Sn4+ + 2 e- ----> Sn2+ Eo = 0.14 V;
I2 + 2 e- ----> 2 I- Eo = 0.53 V |
| | A) | Al3+ |
| | B) | Al |
| | C) | I- |
| | D) | I2 |
| | E) | Sn4+ |
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7 | |
Calculate the free energy change per mole of Cu2+ formed in the following reaction at 25 oC. Cu + 2 Ag+ ----> 2 Ag + Cu2+. Cu2+ + 2 e- ----> Cu Eo = 0.34 V; Ag+ + e- ----> Ag, Eo = 0.80 V. |
| | A) | 0.46 kJ |
| | B) | 89 kJ |
| | C) | 44.5 kJ |
| | D) | -89 kJ |
| | E) | -0.46 kJ |
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8 | |
What is Keq for the reaction Mg(s) + Pb2+ ----> ----> Mg2+ + Pb? Pb2+ + 2 e- ----> Pb, Eo =
-0.13 V; Mg2+ + 2 e- ----> Mg, Eo = -2.37 V. |
| | A) | 5 x 1075 |
| | B) | 3 x 1084 |
| | C) | 2 x 10-75 |
| | D) | None of the above. |
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9 | |
What would you observe if you set up the following electrochemical cell: Ag|AgNO3(0.001 M)|AgNO3(1 M)|Ag? |
| | A) | Electrons will flow from left to right, causing a decrease in the AgNO3 concentration in the left cell, and an increase in the AgNO3 concentration in the right cell. |
| | B) | Electrons will flow from right to left, causing an increase in the AgNO3 concentration in the left cell, and a decrease in the AgNO3 concentration in the right cell. |
| | C) | Electrons will flow from left to right, causing an increase in the AgNO3 concentration in the left cell, and a decrease in AgNO3 concentration in the right cell. |
| | D) | Electrons will flow from right to left, causing a decrease in the AgNO3 concentration in the left cell, and an increase in the AgNO3 concentration in the right cell. |
| | E) | There will be no electron flow because the reduction potential at both electrodes is the same. |
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10 | |
How many grams of the product formed at the cathode in the electrolysis of an aqueous solution of cupric chloride will be produced by a current of 1.0 A operating for 4.0 hrs? |
| | A) | 2.3 g |
| | B) | 4.7 g |
| | C) | 6.9 g |
| | D) | 8.0 g |
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2002 McGraw-Hill Higher Education