Electrochemistry Laboratory Experiment

Please see the attached file for these questions on electrochemistry.

Thank you!

Procedure 1:

1. Identify the cathode and anode in this system.

Cathode (reduction) : Copper
Anode (oxidation): Tin

2. Use the table for standard reduction potential at 25 degrees C. How does the calculated value compare to the experimentally obtained value?

Cu2+ + 2eCu(s) E= 0.337 V
Sn(s)Sn2+ + 2e- E= 0.14 V

E (total) = 0.337 + 0.14 = 0.477 V

E degrees cell E degrees cathode E degrees anode
E degrees cell = 0.337V - (+0.14V)
E degrees cell = 0.197V

How does the calculated value compare to the experimental value?

Experiment:
2 250ml beakers
Beaker #1 150ml CuSO4 (blue)electrode set to Copper
Beaker #2 150 ml SnCl2 (clear) electrode set to Tin
Salt bridge
Volt meter = .4761

3. What does the reduction potential of this cell say about the spontaneity of this redox reaction? Are products or reactants favored? How do you know?

Spontaneity of a chemical reaction is determined by the overall ccell potential Ecell. If Ecell>0, the reaction is spontaneous and if Ecell <0, the reaction will not be spontaneous. This can also be looked at in terms of Gibbs Free Energy (G). If G<0, the reaction is spontaneous and if G>0 then K will be small and the products will be favored. G = -RTin(K). If the reaction is spontaneous, ( G < 0) then K will be small and the products will be favored. (please let me know if I am right)...

E >0 (spontaneous), reactants favored.

Procedure 2:

1. Identify the cathode and anode in this system.

Cathode (reduction) :Silver
Anode (oxidation): Copper

2. Use the table for standard reduction potential at 25 degrees C. How does the calculated value compare to the experimentally obtained value?

From standard reduction table :
Cu2+ + 2e&#61664;Cu(s) E = 0.337 V
Ag(s)&#61664; Ag+ + e- E = -0.7994 V

E (total) = 0.337 + (-0.7994) = -0.4624 V

Cell Potential:
E degrees cell =E degrees cathode -E degrees anode
E degrees cell = 0.7994V - (+0.337)
E degrees cell = 0.4624V

How does the calculated value compare to the experimentally obtained value?

Experiment:
2 250ml beakers
Beaker # 150ml CuSO4 electrode set to Copper
Beaker #2 AgCl electrode set to Silver
Salt Bridge
Volt Meter = -.4594

3. What does the reduction potential of this cell say about the spontaneity of this redox reaction? Are products or reactants favored? How do you know?

E<>0 (non-spontaneous), products favored.

Procedure 3:

1. Identify the cathode and anode in this system.

Cathode (reduction): Copper
Anode (oxidation): Zinc

2. Use the table for standard reduction potential at 25 degrees C. How does the calculated value compare to the experimentally obtained value?

From Standard Reduction table:
Cu2+ + 2e&#61664;Cu(s) E = 0.337 V
Zn(s) &#61664;Zn2+ + 2e- E = 0.763 V

E (total) = 0.337 + (-0.763) = 1.100 V

E degrees cell E degrees cathode E degrees anode
E degrees cell = 0.7994V -(+0.337)
E degrees cell = 0.4624V

How does the calculated value compare to the experimentally obtained value?

Experiment:

2 250ml beakers.
Beaker #1 CuSO4 150 ml Copper
Beaker #2 ZnSO4 electode set to Zinc
Salt Bridge
Volt Meter = 1.103

3. What does the reduction potential of this cell say about the spontaneity of this redox reaction? Are products or reactants favored? How do you know?

E >0 (spontaneous), reactants favored.

Procedure 4:

1. Identify the cathode and anode in this system.

Cathode (reduction): Tin
Anode (oxidation) : Zinc

2. Use the table for standard reduction potential at 25 degrees C. How does the calculated value compare to the experimentally obtained value?
From Standard Reductions table:
Sn2+ + 2e&#61664;Sn(s) E = -0.14 V
Zn(s)&#61664;Zn2+ + 2e- E = 0.763 V

E (total) = -0.14 + 0.763 = 0.623 V

How does the calculated value compare to the experimentally obtained value?

Experiment:
2 250ml beakers
Beaker #1 SnCl2 electrode set to Tin
Beaker #2 ZnSO4 electrode set to Zinc
Volt Meter = .6269

3. What does the reduction potential of this cell say about the spontaneity of this redox reaction? Are products or reactants favored? How do you know?

E > 0 (spontaneous), reactants favored

Procedure 5:

1. Identify the cathode and anode in this system.

Cathode (reduction): Tin
Anode (oxidation): Silver

2. Use the table for standard reduction potential at 25 degrees C. How does the calculated value compare to the experimentally obtained value?

From Standard Reduction table:
Sn2+ + 2e&#61664;Sn(s) E = -0.14 V
Ag(s)&#61664; Ag+ + e- E = -0.7994 V

E (total) = -0.14 + (- 0.7994) = - 0.9394 V

How does the calculated value compare to the experimentally obtained value?

Experiment:
2 250ml beakers
Beaker #1 SnCl2 electode set to Tin
Beaker #2 AgNO3 electrode set to Silver
Volt Meter = -.9357

3. What does the reduction potential of this cell say about the spontaneity of this redox reaction? Are products or reactants favored? How do you know?

E > <0 (spontaneous), products favored

Procedure 6:

1. Identify the cathode and anode in this system.

Cathode (reduction): Silver
Anode (oxidation): Zinc

2. Use the table for standard reduction potential at 25 degrees C. How does the calculated value compare to the experimentally obtained value?

From Standard Reductions table:
Zn2+ + 2e&#61664;Zn(s) E = -0.763 V
Ag(s)&#61664;Ag+ + e- E = -0.7994 V

E (total) = -0.763 + (-0.7994) = -1.5624 V

How does the calculated value compare to the experimentally obtained value?

Experiment:
2 250ml beakers
Beaker #1 ZnSO4 electrode set to Zinc
Beaker #2 AgNO3 electrode set to Silver
Volt Meter = -1.562

3. What does the reduction potential of this cell say about the spontaneity of this redox reaction? Are products or reactants favored? How do you know?

E < >o (non-spontaneous), products favored.

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