📘 IB Understanding
A voltaic (galvanic) cell converts the energy from a spontaneous redox reaction into electrical energy. It consists of two half-cells connected by an external wire and a salt bridge.
Voltaic Cell (Zn/Cu)
Key Components
| Component | Function |
|---|---|
| Anode (−) | Oxidation occurs, electrons leave here |
| Cathode (+) | Reduction occurs, electrons arrive here |
| Salt bridge | Completes circuit; allows ion flow to balance charges |
| External wire | Allows electron flow generating current |
Cell Notation (IUPAC)
Zn(s) | Zn2+(aq) || Cu2+(aq) | Cu(s)
Anode on the left, cathode on the right. | = phase boundary, || = salt bridge.
⚠️ Exam Tip
Remember: AN OX (anode = oxidation), RED CAT (reduction = cathode). In voltaic cells, electrons flow from anode to cathode through the external circuit.