Potencial Nernst Na⁺
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The Nernst Potential Na⁺ calculator determines the electric potential difference generated by a sodium ion (Na⁺) concentration gradient across a cell membrane. The formula used is E = (RT/zF)·ln([Na]out/[Na]in), where R is the gas constant, T is the temperature in kelvin, z is the ion charge (z=1 for Na⁺), F is Faraday's constant, and [Na]out/[Na]in is the ratio of extracellular to intracellular sodium concentrations.
This tool is valuable in cellular physiology studies, particularly for understanding ionic balance in neurons and muscle cells. It helps predict the Na⁺ equilibrium potential, critical for processes like action potential generation. The result depends directly on the concentration ratio and temperature, which must be accurately provided.
When using the calculator, ensure concentration units (typically in mM) are consistent. Temperature must be in kelvin for accurate results. Note that the pure Nernst model does not account for membrane selectivity effects from other ions, which might influence real-world scenarios.
Frequently asked questions
What is the Nernst potential?
It is the electric potential generated by a concentration gradient of a specific ion, calculated using E = (RT/zF)·ln([ion]extracellular/[ion]intracellular).
Why use sodium (Na⁺) in this calculation?
Na⁺ is a common ion in biological processes like nerve impulse conduction and osmotic balance maintenance.
How does temperature affect the result?
Temperature (T in kelvin) is in the formula. Higher temperatures increase the potential, while lower ones decrease it.
Do I need to convert concentrations to mM?
Yes, units must be consistent (mM, mol/L, etc.) for accurate results.
Is the result exact in real-world scenarios?
No. The Nernst model is an approximation; factors like membrane selectivity and other ions may alter the actual potential.