You are the
ONE…
Name______________
Date___________
Period_____
Purpose:
The students will identify and construct different types of electrochemical cells.
Safety Considerations:
Safety is of utmost importance
Electricity can be very dangerous. Do not attempt this lab if you are prone to holding wires in your
mouth while standing in a bucket of water. Never use a computer while swimming.
You should put on your virtual lab goggles.
Materials:
Voltaic part of the lab:
http://www.kentchemistry.com/moviesfiles/Units/Redox/VoltaicCellEMF.htm
electrolysis part of the lab:
http://www.kentchemistry.com/moviesfiles/Units/Redox/voltaiccelll20.htm
Procedure:
Voltaic Cell with concentrations:
1. Construct a data table:
2. Include a column for the cathode, cathode solution, anode solution, anode, # electrons
moved per atom of anode metal, voltage, and cell notation
3. Create 3 galvanic cells using all of the combinations of metals and 1.0 M solutions. If no
electrons move, write N/A in your data table.
4. Now vary the molarity of solutions at the cathode and anode. Record the effect on the cell
voltage as you vary the molarity at the cathode/anode. (You will be asked about this later)
5. Choose your cell that has the highest voltage. Now calculate the voltage if you doubled the
conditions (multiply the highest molarity x2, the lowest molarity x 0.5)
Electrolytic Cell
1. Construct a data table for this experiment which has a column for each variable, predicted
amount of deposition, and starting and ending masses for each electrode.
2. Choose a metal for the cathode and anode, voltage, current, time, and electrolyte.
3. Calculate the amount of deposited material on the anode (show all work) Place in data
table.
4. Click the on button in the experiment, and record the masses of the electrodes at the end of
the time selected.
5. Repeat the procedure for 3 other combinations of electrodes and electrolytes.
Over
Clean up and turn the computer off.
Analysis Questions:
Experiment 1
1) Describe the differences between the two types of cells you used today.
2) What is an electrode potential? What does a negative potential indicate?
3) What is the purpose of the salt bridge? Why must it be connected to both electrolyte
solutions?
4) What combination and molarities resulted in the most active cell? Why?
5) What combinations result in a ‘dead cell’ where no reaction occurred? Explain why no
electrons were moved.
6) Re-order the electrodes you used based on reduction potential. Use Copper as your
standard.
7) Calculate the voltage that the first 3 voltaic cells you created would produce if the molarity
of the anode solution was .0001M instead of 1.0 M
8) What would happen to the voltage if the mass of the electrodes were increased? Explain.
9) Zinc and silver are used in a voltaic cell. Zinc is the anode and Silver is the cathode. If the
concentration of Zinc chloride is 1M, and the voltage across the cell is 0.84 calculate:
a. The concentration of silver in the half cell.
b. The Ksp of silver chloride.
Experiment 2
1)
2)
3)
4)
Describe what current is and what factor it plays in electrolysis.
Is this experiment spontaneous, why or why not?
Describe voltage and its affect on the ability to perform electrolysis.
Calculate the time it would take to plate out 24 grams of Zinc from a zinc sulfate solution
using a 225 amp lawnmower battery. (a lawnmower batter is 12 volts, plenty to make this
reaction happen)
Last Electrochemistry question
1) Describe cathodic protection and how it is used to protect the Tacoma narrows bridges
(chapter 20)
The combined POTENTIAL of you
AP Chemistry folk is absolutely
astounding! I am ELECTRIFIED
by your efforts!