Galvanic Voltaic Cell

Galvanic Voltaic Cell is an interactive 3D electrochemistry laboratory where students assemble spontaneous redox half-cells and measure cell voltage. Two glass beakers hold metal electrodes immersed in their aqueous ion solutions, joined by a glowing KNO3 U-tube salt bridge and an external wire circuit with a digital voltmeter. Students can select or click electrodes to cycle between Magnesium, Zinc, Iron, Copper, and Silver, adjust electrolyte molarity, or drag an electrode out of solution to break the circuit. Live animations show glowing electrons flowing from anode to cathode while K+ cations and NO3- anions migrate through the salt bridge to maintain electrical neutrality.

• Start with the classic Daniell cell (Left = Zn, Right = Cu at 1.0 M) and verify that the voltmeter reads +1.10 V with electrons flowing from Zn to Cu.
• Switch the Left electrode to Magnesium (Mg) and the Right electrode to Silver (Ag) to achieve the maximum standard cell potential of +3.17 V.
• Select the same metal (such as Cu and Cu) for both half-cells and confirm that the cell potential drops to 0.00 V with no net electron flow.
• Drag either metal electrode plate upward out of the electrolyte solution and observe the voltmeter immediately drop to 0.00 V (open circuit).
• Watch the purple K+ and green NO3- ions inside the salt bridge reverse direction when you put Cu on the left and Zn on the right.

1. 1Calculate standard cell potential E°cell = E°(cathode) - E°(anode) from standard reduction potentials.
2. 2Identify the anode as the site of oxidation (more negative E°) and the cathode as the site of reduction (more positive E°).
3. 3Explain why electrons travel through the external wire from anode to cathode while salt-bridge cations migrate toward the cathode beaker.
4. 4Describe what happens to cell voltage when both electrodes are identical or when an electrode loses contact with the electrolyte.

Questions teachers ask