A Zn(s) | Zn^ 2+ (1.0 M) half-cell and a Cu(s) | Cu^ 2+ (1.0 M) half-cell are now…
CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry
Problem
A Zn(s) | Zn^{2+} (1.0 M) half-cell and a Cu(s) | Cu^{2+} (1.0 M) half-cell are now connected to a direct-current power supply that forces current opposite to the spontaneous direction for the cell described in Question 1. The magnitude of the applied potential is large enough to drive the non-spontaneous reaction at 25 °C.
(1) Indicate which electrode is connected to the positive terminal of the power supply and which is connected to the negative terminal. Explain your reasoning in terms of the processes occurring at each electrode.
(2) For this electrolytic operation, identify the electrode at which oxidation occurs and the electrode at which reduction occurs.
(3) Describe the direction of electron flow through the external circuit during electrolysis. Use the metal names in your answer.
(4) The Zn^{2+} concentration is observed to decrease while the Cu metal electrode loses mass. Explain how these observations are consistent with your answers to parts (a)–(c).