Galvanic Cells Notes

Identify that galvanic cells generate an electrical potential difference from a spontaneous redox reaction.

Galvanic Cells: Galvanic cells generate an electrical potential difference because a spontaneous redox reaction occurs, driving electrons from the anode to the cathode through an external circuit.

Explain that galvanic cells can be represented as cell diagrams, including anode and cathode half-equations.

Cell Diagrams: Galvanic cells can be represented using cell diagrams that show the anode and cathode, their half‑equations, and the salt bridge, allowing the redox reaction and electron flow to be clearly visualised.

Explain that oxidation occurs at the negative electrode (anode) and reduction occurs at the positive electrode (cathode).

Where Does Oxidation and Reduction Occur: Oxidation happens at the negative electrode (anode), where electrons are released, and reduction happens at the positive electrode (cathode), where electrons are gained.

Explain that two half-cells can be connected by a salt bridge to create a galvanic cell, e.g. Mg, Zn, Fe and Cu and solutions of their ions.

Formation of a Galvanic Cell: Two separate metal half‑cells (e.g., Mg/Mg²⁺, Zn/Zn²⁺, Fe/Fe²⁺, Cu/Cu²⁺) are connected by a salt bridge and an external wire, allowing electrons to flow between the oxidation and reduction half‑cells so a spontaneous redox reaction can produce electrical energy.

Identify the essential components of a galvanic cell, including the oxidation and reduction half cells, the positive and negative electrodes and their solutions of their ions, the flow of electrons and the movement of ions, and the salt bridge.

Galvanic Cell: A device that converts chemical energy from a spontaneous redox reaction into electrical energy.

Oxidation Half-Cell: The part of the galvanic cell where oxidation occurs (loss of electrons). Contains the anode and a solution of its ions (e.g., Zn(s) in Zn²⁺(aq)).

Reduction Half-Cell: The part of the galvanic cell where reduction occurs (gain of electrons). Contains the cathode and a solution of its ions (e.g., Cu(s) in Cu²⁺(aq)).

Anode (Negative Electrode): Electrode where oxidation happens. Releases electrons into the external circuit. Negative in a galvanic cell.

Cathode (Postive Electrode): Electrode where reduction happens. Receives electrons from the external circuit. Positive in a galvanic cell.

Ion SOlutions: Each half‑cell contains a metal electrode in a solution of its own ions (e.g., Mg/Mg²⁺). Allows oxidation and reduction to occur.

Flow of Electrons: Electrons move from anode → cathode through the external circuit. This flow produces the electrical current.

Movment of Ions: Ions move through the solutions and salt bridge to maintain charge balance as the reaction proceeds.

Salt Bridge: A tube or strip containing an inert electrolyte (e.g., KNO₃). Allows ion movement between half‑cells to prevent charge buildup and complete the internal circuit.

Sketch a galvanic cell and label the essential components.