Electrolytic and Galvanic Cells?
Two half cells in a galvanic cell consists of one iron (Fe(s)) electrode in a solution of iron(II) sulphate (FeSO4(aq)) and a silver (Ag(s)) electrode in a silver nitrate solution.
a) Assume that the cell is operationg as a galvanic cell. State the oxidation half-reaction, the reduction half-reaction, and the overall cell reaction. Remember to eliminate any spectator ions. Describe what will happen to the mass of the cathode and the mass of the anode while the cell is operating.
b) Repeat part a), assuming that the cell is operating as an electrolytic cell.
One Response
a) assuming reduction potentials E°Ag+/Ag = 0.80 V and E°Fe2+/Fe = -0.44 V
cathode (reduction) Ag+ + e- —-> Ag
anode (oxidation) Fe —-> Fe2+ + 2e-
overall cell reaction is
2Ag+ + Fe —> 2Ag + Fe2+
cathode electrode mass reduces
anode electrode mass increases
b) if the cell is operating as electrolytic cell the reactions occurs backward
cathode (reduction) Ag+ + e- —-> Ag
anode (oxidation) Fe —-> Fe2+ + 2e-