faraday

(noun)

The quantity of electricity required to deposit or liberate 1 gram equivalent weight of a substance during electrolysis; approximately 96,487 coulombs.

Related Terms

Examples of faraday in the following topics:

  • Electrostatic Shielding

    • Electrostatic shielding is the phenomenon that occurs when a Faraday cage blocks the effects of an electric field.
    • A Faraday cage is a closed chamber consisting of a conducting material or a mesh of such a material.
    • The action of a Faraday cage may depend on whether or not it is grounded.
    • Electrical linemen often wear suits made of Faraday cages so as to avoid electrocution.
    • Elevators can act as unintended Faraday cages, shielding cell phones and radios from signal from the outside.

  • Electrolysis Stoichiometry

    • It takes 96,485 coulombs to constitute a mole of electrons, a unit known as the faraday (F).
    • This relation was first formulated by Michael Faraday in 1832, in the form of two laws of electrolysis:
    • Thus, one mole of V3+ corresponds to three equivalents of this species, and will require three faradays of charge to deposit it as metallic vanadium ($V^{3+} + 3e^- \rightarrow V$).

  • Thermodynamics of Redox Reactions

  • Resting Membrane Potentials

    • F is the Faraday constant, equal to 96,485 coulombs·mol−1 or J·V−1·mol−1 .
    • Goldman equation: R is the universal gas constant, equal to 8.314 joules·K−1·mol−1 T is the absolute temperature, measured in kelvins (= K = degrees Celsius + 273.15) F is the Faraday constant, equal to 96,485 coulombs·mol−1 or J·V−1·mol−1

  • Faraday's Law of Induction and Lenz' Law

    • The direction (given by the minus sign) of the EMF is so important that it is called Lenz' law after the Russian Heinrich Lenz (1804–1865), who, like Faraday and Henry, independently investigated aspects of induction.
    • Faraday was aware of the direction, but Lenz stated it, so he is credited for its discovery .

  • Cathode Rays

    • In 1838, Michael Faraday passed a current through a rarefied air-filled glass tube and noticed a strange light arc with its beginning at the cathode (negative electrode) and its end almost at the anode (positive electrode).
    • Faraday had been the first to notice a dark space just in front of the cathode, where there was no luminescence.
    • This came to be called the cathode dark space, Faraday dark space, or Crookes dark space.
    • Crookes found that as he pumped more air out of the tubes, the Faraday dark space spread down the tube from the cathode toward the anode, until the tube was totally dark.

  • Van de Graff Generators

    • The sphere acts as a Faraday shield, shielding the upper roller and comb from the electric field produced by charges on the outside of the sphere.

  • Concentration of Cells

    • Here, n is the number of moles of electrons, F is the Faraday constant ($\frac {Coulombs}{mole}$), and ΔE is the cell potential.

  • Conductors and Fields in Static Equilibrium

    • This occurrence is similar to that observed in a Faraday cage, which is an enclosure made of a conducting material that shields the inside from an external electric charge or field or shields the outside from an internal electric charge or field.

  • Induced EMF and Magnetic Flux

    • The apparatus used by Faraday to demonstrate that magnetic fields can create currents is illustrated in the following figure.