Breadcrumb Home > Dictionary > Index A Cite Avogadro's law: Meaning and Definition of Find definitions for: A'voga'dro's law' Pronunciation: [key] — Chem. Chem. 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. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Avogadro Avogadro's number TrendingHere are the facts and trivia that people are buzzing about. January 2021 Current Events: US News The Holocaust (1933–1945) Chinese New Year History, Meaning, and Celebrations Noble Titles and Ranks in a Monarchy The 5 Best Air Purifiers of 2020 Inaugural Trivia Related Content Daily Word Quiz: skein Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language