Cell voltage

Description

A galvanic cell, or voltaic cell, named after Luigi Galvani, or Alessandro Volta respectively, is an electrochemical cell that derives electrical energy from spontaneous redox reactions taking place within the cell. It generally consists of two different metals connected by a salt bridge, or individual half-cells separated by a porous membrane.

Volta was the inventor of the voltaic pile, the first electrical battery. In common usage, the word “battery” has come to include a single galvanic cell, but a battery properly consists of multiple cells.

The standard electrical potential of a cell can be determined by the use of a standard potential table for the two half cells involved. The first step is to identify the two metals reacting in the cell. Then one looks up the standard electrode potential, E0, in volts, for each of the two half reactions. The standard potential for the cell is equal to the more positive E0 value minus the more negative E0 value.

Related formulas

Variables

Ehalfcellhalf-cell voltage(Volt) (dimensionless)
E0standard electrode potential(Volt) (dimensionless)
namount (moles) (dimensionless)
Mn+activity of the metal ion in solution (moles) (dimensionless)