Because there are 5 metals, there are 10 possible cells you can create. Your TA will assign each student one of the possible cells to build and test. Data from each student will then be pooled to allow you to build a potential series of all the metals.

Place 50 mL of 0.1 M KNO₃ in a 250 mL beaker and using a hot plate bring it to a boil. 

Remove the solution from the heat and add 0.50 grams of agar-agar with constant stirring.

Obtain a U-tube from the front counter.

Use a plastic pipet to fill the agar-KNO₃ gel into the inverted U-tube until the gel fills all but 1/2 inch of the tubes. Allow the gel to cool and solidify.

Soak half of some cotton plugs in each of the prespective solutions you are using in your cell.

Fill the 1/2 inch spaces in the tubes with cotton plugs.  Soaked side in. Make sure that the cotton contacts the agar gel and also protrudes from the tubes. Make sure you mark which side of the cell was soaked in which solvent.

Place 30 mL of each of the salt solutions that correspond to the metals being used into large test tubes. Label the test tubes accordingly. Use a ring stand to hold the two test tubes next to each other.

Insert the appropriate salt bridge into the two tubes. Make sure that you place the correct sides of soaked cotton in the correct solutions. Also make sure that the cotton is fully submerged in the salt solution.

Set the multimeter to read as a voltmeter in direct current volts (V_DC).

Using the clips on the voltmeter, connect the voltmeter to the metal strips and the sides of the test tubes. Make sure that the metal pieces are in contact with the solution, but do not submerge the clips in the solution.

Measure the potential of the cell. If the potential is negative, reverse the wire connections with the voltmeter. Report your findings to the rest of your class.

To the set-up add a 400 mL beaker half filled with DI water.

Place the beaker on a hot plate and adjust the cell’s position on the ring stand until both test tubes are partially submerged in the water.