 Langmuir isotherm. Value of constant increases from blue, red, green and brown The Langmuir equation or Langmuir isotherm or Langmuir absorbtion equation relates the coverage or adsorbtion of molecules on a solid surface to gas pressure or concentration of a medium above the solid surface at a fixed temperature. The equation was developed by Irving Langmuir in 1916. The equation is stated as: In chemistry, adsorption of a substance is its concentration on a particular surface. ...
Approximately, the partial pressure of a gas in atmospheres in a mixture or solution is what would be the pressure of that gas if all other components of the mixture or solution suddenly vanished without its temperature changing. ...
Concentration is a very common concept used in chemistry and related fields. ...
Irving Langmuir -- chemist and physicist Irving Langmuir (January 31, 1881 in Brooklyn, New York - August 16, 1957 in Woods Hole, Massachusetts) was an American chemist and physicist. ...
θ or theta is the percentage coverage of the surface, P is the gas pressure or concentration, α or alpha is a constant. Note: A theta probe is a device for measuring soil moisture. ...
Alpha by itself may refer to: The first letter of the Greek alphabet, Α α, which also has some cultural meanings; see alpha (letter). ...
The constant α is the Langmuir adsorption constant and increases with an increase in the strength of adsorption and with a decrease in temperature. The equation is derived starting from the equilibrium between empty surface sites, particles and filled particle sites Equilibrium or balance is any of a number of related phenomena in the natural and social sciences. ...
equilibrium between empty surface sites S* and particles P and filled surface sites S-P
Because the fraction of filled surface sites is equal to θ and the fraction of unfilled sites equal to 1-θ and because P is proportional to the gas pressure or concentration the equation can be rewritten to
Other equations relating to adsorbtion exist such as the Temkin equation or the Freundlich equation.
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Queen Mary, University of London (QMUL) (until recently Queen Mary and Westfield College, University of London and still called that in its charter and occasionally still abbreviated to QMW) is the fourth largest College of the University of London. ...
References - The constitution and fundamental properties of solids and liquids. part i. solids. Irving Langmuir; J. Am. Chem. Soc. 38, 2221-95 1916 First Page
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