PRACTICAL 18 – ELECTROCHEMICAL CELLS Set up half-cells for each of the following electrode reactions: Cu2+(aq) + 2e == Cu(s) Fe2+(aq) + 2e == Fe(s) Al3+(aq) + 3e == Al(s) Mg2+(aq) + 2e == Mg(s) Zn2+(aq) + 2e == Zn(s) Fe3+(aq) + 3e == Fe(s) Use these half-cells to create five electrochemical cells. Choose five cells which allow you to rank all six half-cells from most positive to most negative. Make a note of the emf of each cell, including the sign. Right hand electrode Left hand electrode Emf of cell Write equations for the chemical reaction taking place in each cell. Given that the standard electrode potential for the Cu/Cu half-cell is +0.34V, deduce the standard electrode potentials of the other five half-cells. Hence predict whether the following reactions are feasible: 2Al + 3Mg2+ 2Al3+ + 3Mg Zn + Fe2+ Zn2+ + Fe Fe + 2Fe3+ 3Fe2+ Fe2+ + Cu Fe + Cu2+ Al + Fe3+ Al3+ + Fe From the species in the half-cells above, choose: The strongest oxidising agent The weakest oxidising agent The strongest reducing agent The weakest reducing agent
PRACTICAL 18 – ELECTROCHEMICAL CELLS Set up half-cells for each of the following electrode reactions: Cu2+(aq) + 2e == Cu(s) Fe2+(aq) + 2e == Fe(s) Al3+(aq) + 3e == Al(s) Mg2+(aq) + 2e == Mg(s) Zn2+(aq) + 2e == Zn(s) Fe3+(aq) + 3e == Fe(s) Use these half-cells to create five electrochemical cells. Choose five cells which allow you to rank all six half-cells from most positive to most negative. Make a note of the emf of each cell, including the sign. Right hand electrode Left hand electrode Emf of cell Write equations for the chemical reaction taking place in each cell. Given that the standard electrode potential for the Cu/Cu half-cell is +0.34V, deduce the standard electrode potentials of the other five half-cells. Hence predict whether the following reactions are feasible: 2Al + 3Mg2+ 2Al3+ + 3Mg Zn + Fe2+ Zn2+ + Fe Fe + 2Fe3+ 3Fe2+ Fe2+ + Cu Fe + Cu2+ Al + Fe3+ Al3+ + Fe From the species in the half-cells above, choose: The strongest oxidising agent The weakest oxidising agent The strongest reducing agent The weakest reducing agent