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Avogadro's law

American  

noun

Chemistry.
  1. the principle that equal volumes of all gases at the same temperature and pressure contain the same number of molecules. Thus, the molar volume of all ideal gases at 0° C and a pressure of 1 atm. is 22.4 liters.


Avogadro's law British  

noun

  1. the principle that equal volumes of all gases contain the same number of molecules at the same temperature and pressure

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Avogadro's law Scientific  
/ ä′və-gädrōz /
  1. The principle that equal volumes of all gases under identical conditions of pressure and temperature contain the same number of molecules. Avogadro's law is true only for ideal gases (gases in which there is no interaction between the individual molecules).


Etymology

Origin of Avogadro's law

First recorded in 1870–75; named after A. Avogadro