Nernst equation

Nernst Equation

The Nernst equation is a mathematical formula that describes the equilibrium potential across a cell's membrane. It is named after Walther Nernst, a German physical chemist who first formulated the equation.

Overview

The Nernst equation is fundamental in the field of electrochemistry, as it relates the reduction potential of an electrochemical reaction (half-cell or full cell reaction) to the standard electrode potential, temperature, and activities (often approximated by concentrations) of the chemical species undergoing reduction and oxidation. It has important applications in fields such as neurobiology and cardiology, where it is used to calculate the potential of an ion of charge z across a membrane.

Mathematical Formulation

The Nernst equation is given by:

E = E0 + (RT/nF) ln(Q)

where:

• E is the cell potential,
• E0 is the standard cell potential,
• R is the universal gas constant,
• T is the temperature in Kelvin,
• n is the number of moles of electrons exchanged in the electrochemical reaction (the reaction's stoichiometry),
• F is Faraday's constant, and
• Q is the reaction quotient.

Applications

The Nernst equation plays a crucial role in understanding ionic concentrations within cells and membranes. It is used in physiology for finding the electric potential of a cell membrane with respect to one type of ion.

See Also

• Electrochemical gradient
• Goldman equation
• Hodgkin-Huxley model

References

Nernst equation Resources
Latest articles Most recent articles Ongoing trials	Wikipedia