# Faraday's laws of electrolysis

Michael Faraday studied the process of electrolysis in detail. He published two laws of electrolysis based on this research which are known as **Faraday's laws of electrolysis**.

## Original form

- Faraday's 1
^{st}Law of Electrolysis - The mass of a substance produced at an electrode during electrolysis is directly proportional to the number of electrons (the quantity of electricity) transferred at that electrode.

- Faraday's 2
^{nd}Law of Electrolysis - The number of faradays of electric charge required to discharge one mole of substance at an electrode is equal to the number of "excess" elementary charges on that ion.

## Modern form

In modern form, Faraday's laws are summarised by:

where

*m*is the mass of the substance produced at the electrode*Q*is the total electric charge passed through the solution*z*is the valence number of ions of the substance (electrons transferred per ion)*F*= 96 485 C mol^{-1}is the Faraday constant*M*is the molar mass of the substance

The total charge *Q* is the integral electric current *I*(*t*) over time *t*:

where *T* is the total amount of time of the electrolysis.

In the simple case of constant current electrolysis this reduces to:

and leads to

where *n* is the amount of substance ("number of moles") produced.

## References

- Serway, Moses, and Moyer,
*Modern Physics*, third edition (2005).

## See also

de:Faradaysche Gesetze
el:Νόμος ηλεκτρόλυσης
eo:Leĝo de Faraday
nl:Elektrolysewet van Faraday
uk:Закони Фарадея