Electrochemistry Lab

Purpose:

1. To determine which combination of metals and salt bridges will give us the highest volt reading.

2. To determine an unknown concentration of a solution using the Nernst Equation.

Materials:

Zinc, copper, lead, magnesium, 1 M Solutions of each of the metals, Porous cup, U-tube with salt solution, Voltmeter, alligator clips with wires, hot dog, lemon

Procedures:

Draw out the set up of each possible combination of the metals. Indicate which is the cathode and anode. Also, indicate, the theoretical value of each cell.

Analysis/Conclusion/Calculation Questions

1. Compare your E° cell to the theoretical values. Were they the same or different? If they were different, give a reason why you believe they were different.

2. Did the size of the metal strip change the amount of current recorded?

3. Which type of ion transfer worked the best? Explain why.

4. What would happen to the E°_cell if some magnesium ions were left in the salt bridge when you were testing lead and iron?

5. Using the Nernst equation, solve for the concentration of your unknown.

6. Draw a cell diagram of the combination of metals that gave you the highest voltage. Be sure to include all parts of the cell including anode, cathode, flow of electrons, half reactions for each reaction, and a balanced cell reaction.