Dalton's law [for John Dalton], physical law that states that the total pressure exerted by a homogeneous mixture of gases is equal to the sum of the partial pressures of the individual gases. The partial pressure of a gas is the pressure it would exert if all the other gases in the mixture were absent.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
More on Dalton's law from Fact Monster:
See more Encyclopedia articles on: Physics