Lecture Notes: Structure of the Galvanic (Voltaic) Cell
Overview
A Voltaic Cell uses a spontaneous redox reaction to generate an electric current.
Zinc Electrode (Anode)
Process: Solid Zinc (Zn) turns into Zinc 2+ ions (Zn²⁺).
Reaction: Zn → Zn²⁺ + 2e⁻
Type: Oxidation (loss of electrons)
Electrons left on the Zinc electrode travel through a wire, creating an electric current.
Copper Electrode (Cathode)
Process: Copper 2+ ions (Cu²⁺) gain electrons to form solid Copper.
Reaction: Cu²⁺ + 2e⁻ → Cu
Type: Reduction (gain of electrons)
Redox Reaction
Combining the two half-reactions to form the overall redox reaction:
Reactants: Solid Zinc + Copper 2+ ions
Products: Zinc 2+ ions + Solid Copper
Electrons are transferred from Zinc to Copper across the wire.
Electrodes and Reactions
Anode: Site of Oxidation (loss of electrons)
Mnemonic: "An Ox" (Anode Oxidation)
Cathode: Site of Reduction (gain of electrons)
Mnemonic: "Red Cat" (Reduction Cathode)
Salt Bridge
Contains sulfate anions and sodium cations.
Function:
Anions migrate to the anode.
Cations migrate to the cathode.
Shorthand Notation
Used to represent a Voltaic Cell without drawing the full diagram.
Format:
Anode material → Single vertical line (phase boundary) → Anode ion → Double vertical line (salt bridge) → Cathode ion → Single vertical line → Cathode material