Galvanic Cell ⚡

Electrochemical power from spontaneous redox reactions — Daniell cell & Nernst equation

Anode ion conc. [M²⁺]
0.10 M

Cathode ion conc. [M²⁺]
1.00 M

Temperature
25 °C

External load
1.0 kΩ

E°cell (standard)

— V

E_cell (Nernst)

— V

Current I

— mA

Power P

— mW

ΔG° reaction

— kJ/mol

Reaction quotient Q

—

Electrochemistry & equations

Galvanic (voltaic) cell: converts chemical energy of a spontaneous redox reaction directly into electrical energy. Named after Alesandro Volta and Luigi Galvani.

Daniell cell (Zn/Cu): Anode: Zn(s) → Zn²⁺(aq) + 2e⁻ (E° = +0.76 V oxidation) | Cathode: Cu²⁺(aq) + 2e⁻ → Cu(s) (E° = +0.34 V reduction). E°cell = 0.34 − (−0.76) = 1.10 V.

Nernst equation: E = E° − (RT/nF)·ln(Q), where R = 8.314 J/mol·K, T = temperature, n = electrons transferred, F = 96485 C/mol, Q = [anode ions]/[cathode ions] for typical 2-electrode cell.

Gibbs free energy: ΔG = −nFE. For spontaneous reaction, ΔG < 0 → E > 0.

Salt bridge / porous separator: allows ion migration (Na⁺, K⁺, NO₃⁻) to maintain charge neutrality in each half-cell without direct mixing of solutions.