Henry's law

Henry's law
the principle that at a constant temperature the concentration of a gas dissolved in a fluid with which it does not combine chemically is almost directly proportional to the partial pressure of the gas at the surface of the fluid. Cf. partial pressure.
[1885-90; named after William Henry (1774-1836), English chemist who devised it]

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      statement that the weight of a gas dissolved by a liquid is proportional to the pressure of the gas upon the liquid. The law, which was first formulated in 1803 by the English physician and chemist William Henry (Henry, William), holds only for dilute solutions (solution) and low gas pressures.

      In a very dilute solution, a solute molecule will (with rare exceptions) have only solvent molecules as near neighbours, and the probability of escape of a particular solute molecule into the gas phase is expected to be independent of the total concentration of solute molecules. In this case the rate of escape of solute molecules will be proportional to their concentration in the solution, and solute will accumulate in the gas until the return rate is equal to the rate of escape. With a very dilute gas this return rate will be proportional to the partial pressure of solute. Thus, we expect that, for a solution very dilute in solute, in equilibrium with a gas at very low pressure, the gas pressure will be proportional to the amount of dissolved gas—the relation known as Henry's law. While the above argument is to be considered only suggestive, Henry's law is found experimentally to hold for all dilute solutions in which the molecular species is the same in the solution as in the gas. The most conspicuous apparent exception is the class of electrolytic solutions.

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Universalium. 2010.

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  • Henry's law — Hen·ry s law (henґrēz) [William Henry, English chemist, 1774–1836] see under law …   Medical dictionary

  • Henry's law — noun Chemistry a law stating that the mass of a dissolved gas in a given volume of solvent at equilibrium is proportional to the partial pressure of the gas. Origin C19: named after the English chemist William Henry …   English new terms dictionary

  • Henry's law — /hɛnriz ˈlɔ/ (say henreez law) noun the principle that the mass of a gas dissolved by a given volume of liquid at constant temperature is directly proportional to the partial pressure of the gas. {named after William Henry, 1774–1836, English… …  

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  • Henry — is an English male given name and a surname, derived from Heinrich of Germanic origin. Equivalents in other languages are Henrik (Scandinavian), Eanruig (Scots Gaelic), Enrico (Italian), Henri (French), Enrique (Spanish), Henrik (Hungarian),… …   Wikipedia

  • Henry , William — (1774–1836) British physician and chemist Henry s father, Thomas Henry, was a manufacturing chemist in Manchester and an analytical chemist of some repute. Initially qualifying as a physician from Edinburgh University, Henry practiced for five… …   Scientists

  • law of nature — noun a generalization that describes recurring facts or events in nature (Freq. 3) the laws of thermodynamics • Syn: ↑law • Hypernyms: ↑concept, ↑conception, ↑construct • …   Useful english dictionary

  • Henry, William — ▪ British chemist born Dec. 12, 1775, Manchester died Sept. 2, 1836, Pendlebury, Lancashire, Eng.  English physician and chemist who in 1803 proposed what is now called Henry s law, which states that the amount of a gas absorbed by a liquid is in …   Universalium

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