Electrochemical cells convert chemical energy into electrical energy (or vice versa) through spatially separated oxidation and reduction half-reactions: oxidation occurs at the anode (electron loss, increase in oxidation number) and reduction occurs at the cathode (electron gain, decrease in oxidation number), with electrons flowing through an external circuit and ions migrating through a salt bridge to maintain charge neutrality. Faraday's law relates the quantity of electric charge passed through the system to the moles of electrons transferred, and hence to the mass of reactant consumed or product deposited at each electrode, while cell potential (EMF) links the electrochemical driving force to Gibbs free energy via ΔG = -nFE. This subject sits within chemical thermodynamics and redox chemistry, building on oxidation-number assignment rules and acid-base equilibrium concepts (such as pKa-dependent protonation state) from the broader study of chemical reactivity.
Electrochemical cells convert chemical energy into electrical energy (or vice versa) through spatially separated oxidation and reduction half-reactions: oxidation occurs at the anode (electron loss, …