AP Chemistry : Thermodynamics
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Example Questions
Example Question #1 : Cell Potential Under Non Standard Conditions
Calculate the standard cell potential of the following reaction:
3 F2 (g) + 2 Au (s) -> 6 F- (aq) + 2 Au3+
Given:
F2 (g) + 2 e- -> 2 F- (aq) Eo = 2.87 V
Au3+(aq)+ 3 e--> Au (s) Eo = 1.50 V
-5.61 V
4.37 V
5.61 V
-1.37 V
1.37 V
1.37 V
Eocell = Eo cathode - Eoanode
Eocell = 2.87 – (1.50) = 1.37 V
Example Question #131 : Thermochemistry And Kinetics
Determine the Ecell for the following reaction at 25 C:
Zn (s) + 2 VO2+ (aq) + 4 H+ -> 2 VO2+ (aq) + Zn2+(aq) + 2 H2O (l)
Given that:
VO2+ (aq) + 2 H+ (aq) + e- -> VO2+(aq) + H2O (l) Eo = 1.00 V
Zn2+ (aq) + 2 e--> Zn (s) Eo = -0.76 V
And
[ VO2+] = 2.0 M; [H+] = 0.50 M; [VO2+] = 1.0 x 10-2M; [Zn2+] = 1.0 x 10-1M
2.41 V
1.76 V
0.95 V
3.71 V
1.89 V
1.89 V
Example Question #1 : Electrolysis And Faraday's Law
How many grams of Cr can be obtained by the electrolysis of a Cr(NO3)3 if 10 amps are passed through the cell for 6 hours?
12.5 g
56.3 g
38.8 g
19.4 g
103 g
38.8 g
Example Question #685 : Ap Chemistry
How much Al would be precipitated if an AlCl3 solution was electrolyzed for 1.00 hours with 5.00 amps?
6.72 g
0.84 g
1.25 g
1.68 g
3.36 g
1.68 g
Example Question #1 : Electrolysis And Faraday's Law
What current must be past through a solution of AlCl3 for 1.19 hours to produce 40g of solid Al?
50.0 amps
100. amps
10.5 amps
75.3 amps
125 amps
100. amps
Example Question #2 : Electrolysis And Faraday's Law
In the electrolysis of CaCl2 a 1.15 amp current is passed through the cell for 5.0 hours. How much Ca is produced?
18.3 g
8.6 g
1.1 g
4.3 g
2.2 g
4.3 g
Example Question #1 : Electrolysis And Faraday's Law
How long would it take to electroplate 28.3g of silver at a constant current of 2.0 amps from a solution of silver nitrate?
422 min
211 min
844 min
53 min
105 min
211 min
Example Question #1 : Galvanic (Voltai) And Elecrolytic Cells
Consider the following electrolytic cell:
What happens at the anode in the electrolytic cell?
Iron is reduced
Nickel is reduced
Nickel is oxidized
Iron is oxidized
Nickel is oxidized
It does not matter if the cell is galvanic or electrolytic; oxidation will always take place at the anode. This means that the nickel loses two electrons and is oxidized at the anode to generate nickel ions.
Nickel ions and iron are products, and are neither oxidized nor reduced during the reaction. Iron ions are reduced at the cathode to generate the iron product.
Example Question #2 : Galvanic (Voltai) And Elecrolytic Cells
Consider the following reaction in a galvanic cell:
Which of the following takes place at the anode?
Zinc is reduced
Zinc is oxidized
Copper is reduced
No reaction takes place at the anode
Copper is oxidized
Zinc is oxidized
Oxidation takes place at the anode and reduction takes place at the cathode. You can remember this with the pneumonic "An Ox, Red Cat."
In the equation, zinc loses electrons. It goes from a neutral, elemental charge to a charge of 
Example Question #2 : Galvanic (Voltai) And Elecrolytic Cells
Toward which pole do electrons travel in a galvanic cell?
More information is needed
Electrons do not travel; only the protons travel
Towards the cathode
Towards the anode
Towards the negative pole
Towards the cathode
Reduction always occurs at the cathode, and oxidation always occurs at the anode. Since reduction is the addition of electrons, the electrons must flow toward the site of reduction.
In a galvanic cell the positive charge is on the cathode, while the negative charge is on the anode. Since a galvanic cell has a positive potential and is spontaneous, electrons freely flow down their potential gradient. The electrons, which are negatively charged, are traveling towards the cathode, which is positive charged, since opposites attract.
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