Observations:
Cell 1
Zn(s) │Zn2+(aq) ║ Cu2+(aq) │Cu(s)
Anode
Zn(s)--->Zn2+(aq)
Cathode
Cu2+(aq)--->Cu(s)
Reduction Half Rxn
Cu2+(aq) + 2e- --->Cu(s)
Oxidation Half Rxn
Zn(s) --->Zn2+(aq) +2e-
Net Cell Rxn
Cu2+(aq) +Zn(s) --->Zn2+(aq)+2e-
Predicted Standard Cell Potential
1.1V
Observed Cell Potential
1.11V
Cell 2
Zn(s) │Zn2+(aq) ║ Fe2+(aq) │Fe(s)
Anode
Zn(s) -->Zn2+(aq)
Cathode
Fe2+(aq) --->Fe(s)
Reduction Half Rxn
Fe2+(aq)+2e--->Fe(s)
Oxidation Half Rxn
Zn(s)-->Zn2+(aq)+2e
Net Cell Rxn
Fe2+(aq) +Zn(s)---> Zn2+(aq)+Fe(s)
Predicted Standard Cell Potential
0.31V
Observed Cell Potential
0.310V
1. Choose two cells from the virtual lab and hand draw a diagram of each cell. Your cell should include two beakers, a salt bridge, wire, voltmeter, anode and cathode.
Label the Anode and Cathode
Include the direction of electron movement
Include direction of cations and anions
2. Compare the predicted standard cell potentials with the observed values. Was there a discrepancy? Provide possible reasons for any differences.
3. Suggest a reason why very small voltaic cells were constructed for this investigation.
4. Would you expect a difference in the cell potential had larger cells been constructed and tested? Suggest an aspect of a cell’s function that may be affected by using a larger cell that contains a greater quantity of chemicals.
5. A Ni-Cd rechargeable cell has a cell potential of +1.30V. If the cathode has a potential of +0.49 V, what is the anode’s potential?
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