Standard Cell Potential

What is this formula?

The standard cell potential is the voltage produced by an electrochemical cell under standard conditions.

It is calculated as the difference between the standard reduction potential of the cathode and the standard reduction potential of the anode.

When to use it

Use this formula when evaluating galvanic cells, predicting reaction spontaneity, comparing electrochemical systems, and designing batteries.

Example

Given:

E°cathode = +0.80 V

E°anode = -0.34 V

Formula:

E° = E°cathode − E°anode

Substitution:

E° = 0.80 − (-0.34)

Result:

E° = 1.14 V

The electrochemical cell has a standard potential of 1.14 volts.

Applications

Electrochemistry

Battery design

Corrosion analysis

Fuel cells

Electroplating

Chemical thermodynamics

Note

Standard conditions generally correspond to:

Temperature = 25°C (298.15 K)

Pressure = 1 bar

Solute activity = 1

All tabulated electrode potentials are standard reduction potentials. The anode potential is not reversed before substitution into the equation; the subtraction automatically accounts for the oxidation occurring at the anode.

A positive standard cell potential indicates a thermodynamically spontaneous galvanic cell under standard conditions.