Avogadro's law

WordReference Random House Unabridged Dictionary of American English © 2025

A′voga′dro's law′, [Chem.]

1. Chemistry 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.

• named after A. Avogadro 1870–75

Collins Concise English Dictionary © HarperCollins Publishers::

Avogadro's law, Avogadro's hypothesis noun

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