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Faraday's law
Faraday's law physical law stating that the number of moles of substance produced at an electrode during electrolysis is directly proportional to the number of moles of electrons transferred at that electrode; the law is named for Michael Faraday, who formulated it in 1834. The amount of electric charge carried by one mole of electrons (6.02 x 10 23 electrons) is called the faraday and is equal to 96,500 coulombs . The number of faradays required to produce one mole of substance at an electrode depends upon the way in which the substance is oxidized or reduced (see oxidation and reduction ). For example, in the electrolysis of molten sodium chloride, NaCl, one faraday, or one mole, of electrons is transferred at the cathode to one mole of sodium ions, Na + , to form one mole of sodium atoms, Na, while in the electrolysis of molten magnesium chloride, MgCl 2 , two faradays of electrons must be transferred at the cathode to reduce one mole of magnesium ions, Mg +2 , to one mole of magnesium atoms, Mg. |
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"Faraday's law." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. "Faraday's law." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1E1-Faradays.html "Faraday's law." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-Faradays.html |
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Faraday's laws
Faraday's laws Two laws of electrolysis and three of electromagnetic induction, formulated by Michael Faraday. The electrolysis laws state that (1) the amount of chemical change during electrolysis is proportional to the charge of electricity passed, and (2) the amount of chemical change produced in a substance by a certain amount of electricity is proportional to the electrochemical equivalent of that substance. Faraday's laws of induction state that (1) an electromagnetic force is induced in a conductor if the magnetic field surrounding it changes, (2) the electromagnetic force is proportional to the rate of change of the field, and (3) the direction of the induced electromagnetic force depends on the field's orientation.
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"Faraday's laws." World Encyclopedia. 2005. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. "Faraday's laws." World Encyclopedia. 2005. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O142-Faradayslaws.html "Faraday's laws." World Encyclopedia. 2005. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-Faradayslaws.html |
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Faraday effect
Faraday effect The rotation of the plane of polarization of an electromagnetic wave as it passes through a region containing free electrons and a magnetic field; also known as Faraday rotation. The amount of rotation, in radians, is given by RM λ2, where RM is the rotation measure of the source and λ is the wavelength. Observation of the Faraday effect in pulsars is the most important means of determining the magnetic field of the Galaxy. It is named after the English physicist Michael Faraday (1791–1867).
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Cite this article
"Faraday effect." A Dictionary of Astronomy. 1997. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. "Faraday effect." A Dictionary of Astronomy. 1997. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O80-Faradayeffect.html "Faraday effect." A Dictionary of Astronomy. 1997. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-Faradayeffect.html |
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