a unit of osmotic pressure used in physical chemistry, cell biology, and medicine. If chemical solutions are separated by a semipermeable membrane (a membrane that resists the passage of dissolved substances but permits the passage of the solvent, usually water), then the solvent will diffuse across the membrane to equalize the concentrations. This process is called osmosis. Solutions with higher concentrations of dissolved substances are said to have higher osmotic pressure than solutions having lower concentrations; thus the solvent moves from an area of low osmotic pressure to an area of higher osmotic pressure. One osmole is the osmotic pressure of a one molar solution (that is, a solution with a concentration of one mole per liter of solvent) of a substance that does not dissociate, such as sugar (glucose) in water. Osmotic pressure depends on the total number of dissolved particles, so for a substance that dissociates into two ions, such as ordinary salt (sodium chloride), a one molar solution has an osmotic pressure of 2 osmoles. In practice, most measurements are in milliosmoles (mOsm). Typical values range from 20 mOsm for fresh water through 290 mOsm for typical human blood plasma to 1010 mOsm for salt water from the open ocean.

Dictionary of units of measurement. 2015.

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  • osmole — ● osmole nom féminin Pression osmotique d une mole dissoute dans un litre d eau sous 22,4 atmosphères à 0 degré centigrade. osmole [ɔsmɔl] n. f. ÉTYM. Av. 1959; de os(mose) ou 2. osmo , et mole. ❖ ♦ Didact. (phys.). Unité de mesure de la pression …   Encyclopédie Universelle

  • Osmole — Une osmole est une mole de particule effectivement en solution. La nécessaire distinction tient du fait qu on utilise des concentrations molaires de soluté non dissous. Par exemple, une solution à 1 mol/L de NaCl correspond à une osmolarité de 2… …   Wikipédia en Français

  • osmole — noun A unit of measurement, a mole of an osmotically active compound. One osmole is the number of osmotically active particles that when dissolved in 22.4L of solvent at 0 degrees celsius exerts an osmotic pressure of 1 atmosphere …   Wiktionary

  • osmole — The molecular weight of a solute, in grams, divided by the number of ions or particles into which it dissociates in solution. * * * n. a unit of osmotic pressure equal to the molecular weight of a solute in grams divided by the number of ions or… …   Medical dictionary

  • osmole — noun see osmol …   New Collegiate Dictionary

  • osmole — os·mole …   English syllables

  • osmole — n. a unit of osmotic pressure equal to the molecular weight of a solute in grams divided by the number of ions or other particles into which it dissociates in solution …   The new mediacal dictionary

  • osmole — noun see osmol …   Useful english dictionary

  • Osmole (unit) — This article is about the osmole unit. For the osmolarity, see Osmolarity. In chemistry, the osmole (Osm or osmol) is a non SI unit of measurement that defines the number of moles of a chemical compound that contribute to a solution s osmotic… …   Wikipedia

  • Осмоль (Osmole) — единица осмотического давления, равная молекулярной массе растворенного вещества в граммах, деленной на число ионов или других частиц, на которые оно диссоциирует в растворе.ОСМОРЕЦЕПТОР (osmoreceptor) группа клеток (нейронов) гипоталамуса,… …   Медицинские термины

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