Experiment: Voltaic Cells

Objective

• Compare the theoretical cell potential of voltaic cells to the experimental measurement of the cell potential.

Equipment and Materials

• Voltage sensors connected to LabQuest
• Beakers with different solutions
• Electrodes (zinc, copper, and silver wires)
• Salt bridges (filter paper in potassium nitrate solution)

Voltaic Cell 1

• Anode: Zinc wire in 0.1 M zinc solution
• Cathode: Copper wire in 0.1 M copper solution
• Calibration:
  • Connect red and black probes to set zero voltage.
  • Attach black probe to anode (zinc) and red probe to cathode (copper).
• Procedure:
  • Use salt bridge between solutions.
  • Record cell potential using LabQuest.
  • Temperature: 25.4°C

Voltaic Cell 2

• Solution Change: 0.05 M zinc solution (diluted from 0.1 M)
• Cathode: Same as Cell 1
• Procedure:
  • Connect with a new salt bridge.
  • Record cell potential (0.90 V)
  • Temperature: 25.6°C

Voltaic Cell 3

• Anode: Silver wire in 0.1 M silver solution
• Cathode: Same as previous cells
• Procedure:
  • Connect with a new salt bridge.
  • Record negative cell potential (around -0.38 V)
  • Temperature: 25.5°C

Voltaic Cell 4

• Solution Change: 0.05 M silver solution
• Procedure:
  • Connect with a new salt bridge.
  • Record negative cell potential (around -0.37 V)
  • Temperature: 25.3°C

Voltaic Cell 5

• Anode: Zinc wire in 0.1 M zinc solution
• Cathode: Silver wire in 0.05 M silver solution
• Procedure:
  • Connect with a new salt bridge.
  • Record positive cell potential (1.34 V)
  • Temperature: 25.2°C

General Notes

• Calibrate sensors to zero between experiments.
• Ensure electrodes are stable to get a stable cell potential reading.
• Dispose of solutions in lab waste containers.
• Dispose of salt bridges in regular trash bins.

Conclusion

• Record all measured cell potentials and temperatures.
• Use these values in the Nernst equation for further calculations.