A student assembles a galvanic cell using a strip of metallic zinc placed in a 1.0 M Zn2+ solution and a strip of metallic copper placed in a 1.0 M Cu2+ solution. The two half-cells are connected by a salt bridge and by an external wire that permits electron flow.
Standard reduction potentials (25 °C):
Zn2+ + 2 e⁻ → Zn(s) E° = −0.76 V
Cu2+ + 2 e⁻ → Cu(s) E° = +0.34 V
(a) Identify which electrode acts as the cathode and which acts as the anode under standard conditions. Justify your answer based on the numerical values of the standard reduction potentials.
(b) Explain qualitatively whether the overall redox reaction occurring in this galvanic cell is thermodynamically favorable under standard conditions. In your explanation, reference the mathematical relationship between the standard cell potential E°cell and the standard free-energy change ΔG°.