Question

A Fe₃⁺/Fe half-cell and Sn₂⁺/Sn half-cell under standard state conditions are connected by a wire and a 0.1 M NaNO₃ salt bridge (assume 298 K).

a. Sketch this galvanic cell with beakers, indicating the direction of electron flow and ion flow from the salt bridge.
b. Write the anode and cathode half-reactions as well as the balanced equation for the redox reaction occurring for the galvanic cell.

Answer 1

In the Fe₃⁺/Fe and Sn²⁺/Sn galvanic cell, the anode half-reaction is Fe → Fe₃⁺ + 3e-, and the cathode half-reaction is Sn²⁺ + 2e- → Sn. The overall cell reaction is 2Fe + 3Sn²⁺ → 3Sn + 2Fe₃⁺. The electron flow is from the anode (Fe) to the cathode (Sn).

Step-by-step explanation:

A Fe₃⁺/Fe and Sn²⁺/Sn galvanic cell consists of two half-cells, each containing a metal electrode in a solution with its respective ions, connected by a wire and a salt bridge. The direction of electron flow is from the anode to the cathode, while in the salt bridge, the ions move to maintain charge neutrality in the solutions. To sketch this cell, draw two beakers with respective metal electrodes, connected by a wire and a salt bridge labeled with NaNO₃. Point the electron flow from anode to cathode with an arrow along the wire. Show ions moving within the bridge from the anode to the cathode side, counterbalancing the movement of electrons.

The half-reactions for the anode and cathode are:

• Anode (oxidation): Fe → Fe₃⁺ + 3e⁻
• Cathode (reduction): Sn²⁺ + 2e⁻ → Sn

The balanced overall redox reaction is:

2Fe + 3Sn²⁺ → 2Fe₃⁺ + 3Sn