Alex’s Notes
Back to Chapter 17 · The Electron Exchange

Complete the zinc-copper circuit

Follow the charge carriers in a zinc–copper galvanic cell. Electrons and ions take different paths.

Chapter 1730-second guided sequenceExplore at your own pace
Alex’s walkthrough

Read the sequence

  1. At the zinc anode, Zn(s) → Zn²⁺(aq) + 2e⁻. Zinc loses mass as metal enters solution.
  2. Electrons travel through the wire from the zinc anode to the copper cathode.
  3. At the copper cathode, Cu²⁺(aq) + 2e⁻ → Cu(s). Copper is deposited and the electrode gains mass.
  4. NO₃⁻ from the salt bridge enters the zinc compartment; K⁺ enters the copper compartment. These ion movements help prevent charge buildup so the current can continue.

About this model. This is a coordinated, idealized inventory diagram, not a timing model. Electrons do not travel through the salt bridge or bulk solution. Anode always means oxidation and cathode reduction; the negative/positive signs shown here apply to a galvanic cell.

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