Purpose: To understand how both voltaic and electrolytic cells function. Procedure: Refer to pages 34-36 of laboratory notebook for experimental details Results and Discussion:
Voltaic Cell Reactions| | |
Overall Cell Reaction| Observed Voltage| Theoretical Voltage| Cu2+(aq)+Zn(s) Cu(s)+Zn2+(aq)| 0.947 V| 1.10 V|
Cu2+(aq)+Sn(s)Cu(s)+Sn2+(aq)| 0.571 V| 0.473 V|
Cu2+(aq)+Fe(s) Cu(s)+Fe2+(aq)| 0.512 V| 0.777 V|
Cu2+(aq)+Mg(s) Cu(s)+Mg2+(aq)| 1.598 V| 2.707 V|
Cu2+(aq)+Pb(s) Cu(s)+Pb2+(aq)| 0.651 V| 0.463 V|
Concentration Cell | Based on Cu2+ - Cu| Cell Reaction| | [Cu2+] anode| [Cu2+] cathode| Observed Voltage| Theoretical Voltage| 1.0 M| 1.0 M| 0.00 V| 0.00 V|
0.10 M| 1.0 M| 0.018 V| 0.030 V|
0.010 M| 1.0 M| 0.036 V| 0.059 V|
In this experiment, the cell potential of five different voltaic cells were determined by a theoretical calculation as well as an experimental test. In all of these voltaic cells, copper was present as the cathode, and the anode was either Zn, Sn, Fe, Mg or Pb. The electrode with the most positive reduction potential in its half reaction had acted as the best oxidizing agent, or was the most likely to be reduced. For this experiment, copper was the best oxidizing agent, with a reduction potential of +.337 V. Copper was reduced in every reaction, also proving that it was the strongest oxidizing agent. The electrode with the most positive oxidation potential in its half reaction had reacted as the best reducing agent, or was more likely to be oxidized. The best reducing agent in this experiment was Mg, with a oxidation potential of 2.37 V. This was also proven in the experimental results, the reaction between copper and magnesium had yielded the highest voltage.
The second part of this experiment had included voltaic cells under non-standard conditions, or 2 copper electrodes were tested with different concentrations of the...