NAME______________________________ SECTION ________ T.A. _____________________

ELECTROLYSIS PRELAB ASSIGNMENT

Computer Activity 1 http://www.chem.iastate.edu/ChemEdGroup/GREENBOWE/sections/projectfolder/flashfiles/redox/home.html

To start the animation click-on "start". Click on "Activity 1". Then click on "Activity 3" and select nickel. You will see four nickel bars that will be immersed into four different solutions. Follow the instructions on the screen and write down your observation (e.g. what reactions occurred or did not occur).

a) For each reaction that occurred for the nickel metal, write a balanced chemical equation. If no reaction occurred, write the two reactants followed by an arrow, then "NR".

b) Choose a reaction that occurred and choose a reaction that did not occur. Use the values of E° in a standard reduction potential table for the half-reactions. (even for the reaction that did not occur). Calculate Efor your reaction and non-reaction. Be sure to include the correct sign.

c) Is there a pattern between the reactivity of metals and the value and sign of E? Explain.

Computer Activity 2 http://www.chem.iastate.edu/ChemEdGroup/GREENBOWE/sections/projectfolder/flashfiles/electroChem/electrolysis10.html

a) Will nickel metal spontaneously react with aqueous nickel(II) nitrate? Set-up an electrolysis experiment. Connect two strips of nickel metal to a power supply and immersed the electrodes in aqueous nickel(II) nitrate. Select the mass of each electrode and record the initial mass of each electrode. Your goal is to cause a non-spontaneous reaction to occur. Before running the simulation, predict what will happen when the power is turned on. Complete the diagram. Identify the metal used for each electrode. Indicate the direction of the flow of electrons in the wire and indicate what will happen at each electrode. Identify the anode and the cathode. Write the half-reactions that will occur.

b) Set the voltage and the current on the power supply. Select the amount of time you want the current to flow. Turn on the power supply. At the end of the experiment, record the final mass of each electrode. Did your predictions match what happened?

c) Will nickel metal spontaneously react with aqueous iron(II) nitrate? Set-up another electrolysis experiment. Use a nickel electrode and an iron electrode immersed in aqueous iron(II) nitrate. Your goal is to set-up the electrodes so that iron metal will be deposited on the nickel electrode when the power supply is turned on. Complete the diagram. Indicate the direction of the flow of electrons in the wire and indicate what will happen at each electrode. Identify the metal used for each electrode. Identify the anode and the cathode. Write the half-reactions and the balanced chemical equation. What is the minimum voltage, Eš, necessary to cause this reaction to occur?