Galvanic cells

Science

Definition

An electrochemical cell that converts chemical energy into electrical energy through a spontaneous redox reaction. It consists of two half-cells connected by a salt bridge, with an anode (oxidation) and a cathode (reduction).

How It Works

  1. Oxidation occurs at the anode, releasing electrons
  2. Electrons flow through an external wire from anode to cathode
  3. Reduction occurs at the cathode, consuming electrons
  4. A salt bridge maintains electrical neutrality by allowing ion flow between half-cells
  5. The cell produces voltage until reactants are consumed

Examples

  • A standard zinc-copper cell with Zn anode and Cu cathode
  • Alkaline batteries powering a flashlight
  • Car batteries using lead-acid galvanic cells
Key Fact

E°cell = E°cathode − E°anode; positive E°cell means spontaneous reaction

Related Terms

Electrolysis Electronegativity Reaction types Ionic bonds

Study This Concept

Practice galvanic cells with free review games in these units:

AP Chemistry Unit 9: Applications of Thermodynamics