Faraday constant
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In physics and chemistry, the Faraday constant is the amount of electric charge in one mole of electrons. The Faraday constant was named after British scientist Michael Faraday. It is used in electrolytic system calculations to determine the mass of a chemical species that will collect at an electrode.
It has the symbol F, and is given by
- ,
where NA is Avogadro's number (approximately 6.02×1023 mole-1) and q is the magnitude of the charge on an electron (approximately 1.602×10−19 coulombs per electron).
The value of F was first determined by weighing the amount of silver deposited in an electrochemical reaction in which a measured current was passed for a measured time. This value was used to calculate Avogadro's number. Research is continuing into more accurate ways of determining F, and thereby NA. There are plans to use this value to redefine the kilogram in terms of a known number of atoms. [Source: NPL Annual Review 1999]
- F = 96,485.3383(83) coulomb/mole
[edit] See also
[edit] Reference
Peter J. Mohr, and Barry N. Taylor, CODATA Recommended Values of the Fundamental Physical Constants: 2002, Rev. Mod. Phys. vol. 77(1) 1-107 (2005)