Loschmidt constant
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In chemistry and physics, the Loschmidt constant (symbol:n0) is the number density of particles (atoms or molecules) of an ideal gas at standard temperature and pressure.[1] It is given by the relationship;
-
- n0 = P/(kBT)
where;
-
- P is the gas pressure
- T is the gas temperature
- kB is the Boltzmann constant
The currently accepted value is;
-
- n0 = (2.686 7774 ± 0.000 0047)×1025 m−3 (CODATA 2006 value at T=273.15K and p=101.325kPa )
It is named after the Austrian chemist Johann Josef Loschmidt, who first calculated its value in 1865.[2]
The term Loschmidt constant is also sometimes (incorrectly) used to refer to the Avogadro constant, particularly in German texts. The Loschmidt constant and the Avogadro constant are related by
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- NA = n0/na
where;
-
- NA is Avogadro's constant
- na is the molar density of the gas in moles per unit volume
[edit] References
- ^ National Institute of Standards and Technology (February 2006). Fundamental physical constants: Physico-chemical constants. Retrieved on 2006-12-28.
- ^ Bader, Alfred; Parker, Leonard. "Joseph Loschmidt, Physicist and Chemist". Physics Today Online (March 2001).
