/ Dictionary / Index R Raoult's law: Meaning and Definition of Find definitions for: Ra•oult's' law' Pronunciation: (rä-lz'), [key] — Physical Chem. Physical Chem. the principle that the fraction by which the vapor pressure of a solvent is lowered by the addition of a nonvolatile, nonelectrolytic solute is equal to the mole fraction of the solute in the solution. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. raob rap Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language