WordNet (r) 3.0 (2006):

law of partial pressures
    n 1: (chemistry and physics) law stating that the pressure
         exerted by a mixture of gases equals the sum of the partial
         pressures of the gases in the mixture; the pressure of a
         gas in a mixture equals the pressure it would exert if it
         occupied the same volume alone at the same temperature
         [syn: Dalton's law, Dalton's law of partial pressures,
         law of partial pressures]