Electrochemistry Cell Builder

Explore how electrode choice controls energy and electron transfer. A zinc/copper cell is ready to run when you open the lab.

1. Observe one event. Press Step once. Notice which electrode loses atoms and which gains them. Oxidation is always at the anode; reduction is always at the cathode.
2. Compare one change at a time. Choose zinc/silver, or swap left and right. Does moving a metal change its role or E°? Use the calculation drawer to connect the voltage to standard reduction potentials.
3. Reverse the reaction. Choose electrolytic mode. The cell potential becomes negative, and the applied supply must exceed its magnitude. Anode and cathode signs reverse; their oxidation/reduction definitions do not.
4. Test the circuit. Disconnect the salt bridge. Why does sustained electron flow stop? Reconnect it and follow K⁺ toward the cathode and NO₃⁻ toward the anode.
5. Build your own. Select a metal and tap its Place button, or drag it to a beaker. Match each electrode to its ionic solution. Clear bench removes the setup; Restart particles keeps it.

Run plays a short 12-event sample. Pause freezes it; Step once works without motion. Slow speed and the ion/explanation switches help you focus. Your device’s reduced-motion setting stops traveling markers; the event counts and particle changes remain available.

Scope: selected metal/ion couples at 25 °C and unit ion activity (approximately 1 M). The powered mode excludes competing water reactions, resistance and overpotential. The voltmeter reports calculated E° for the selected reaction, not terminal voltage under load. The load and meter branch are schematic.