NOTICE: Citizendium is still being set up on its newer server, treat as a beta for now; please see here for more.
Citizendium - a community developing a quality comprehensive compendium of knowledge, online and free. Click here to join and contribute—free
CZ thanks our previous donors. Donate here. Treasurer's Financial Report -- Thanks to our content contributors. --

Faraday constant

From Citizendium, the Citizens' Compendium
(Redirected from Faraday's constant)
Jump to: navigation, search
This article is a stub and thus not approved.
Main Article
Talk
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
 
This editable Main Article is under development and not meant to be cited; by editing it you can help to improve it towards a future approved, citable version. These unapproved articles are subject to a disclaimer.

In chemistry and physics, the Faraday constant F is the amount of charge (in absolute value) in one mole of electrons or one mole of monovalent (singly charged) ions. Its value[1] is

where NA is Avogadro's constant and e is the charge of an electron.

The constant F must be carefully distinguished from the unit F (the faraday) which is a unit of capacitance.

The constant and the unit are named after the British physicist Michael Faraday.

Before electrons were discovered and a value for Avogadro's number was known, Faraday discovered (1833) that in electrolysis the amount of charge F necessary to deposit one mole of monovalent ions on an electrode (cations on the cathode, anions on the anode) is always the same, irrespective of the kind of ions. For a long time weighing the amount of silver—which in solution is the cation Ag+—deposited during electrolysis was the accepted manner of measuring electric charge and electric current.

Reference

  1. Obtained from NIST on December 16, 2007