A galvanic cell is constructed under standard conditions by placing a strip of zinc metal in a 1.0 M Zn2+ solution and a strip of copper metal in a 1.0 M Cu2+ solution. The overall reaction that occurs is
Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)
The standard Gibbs free-energy change for this reaction is −212 kJ mol⁻¹.
Answer the following questions about this electrochemical system.
(a) Determine whether the cell described operates as a galvanic (voltaic) cell or as an electrolytic cell. Justify your answer with reference to the numerical value of the standard Gibbs free-energy change.
(b) Describe the direction of energy conversion that occurs while the cell is operating. Identify the form of energy produced and the form of energy consumed.
(c) Identify the anode and cathode for the cell, stating clearly which half-reaction occurs at each electrode.
(d) Describe two observable macroscopic changes (other than temperature change) that would be expected as the cell delivers current. Explain the chemical basis for each observation.