osmotic pressure

pressure placed on a semipermeable membrane by the passage of a solution into a pure solvent

Osmotic pressure is the hydrostatic pressure produced by a solution in a space divided by a semipermeable membrane due to a differential in the concentrations of solute.Osmotic potential is the opposite of water potential with the former meaning the degree to which a solvent (usually water) would want to stay in a liquid. When a biological cell is in a hypotonic environment (the cell interior contains a lower concentration of water and a higher concentration of other molecules than its exterior), water flows across the cell membrane into the cell, causing it to expand due to osmotic pressure. In plant cells, the cell wall restricts the expansion, resulting in pressure on the cell wall from within called turgor pressure. The osmotic pressure π of a dilute solution can be calculated using the formula
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Osmotic pressure n. The pressure exerted by the flow of water through a semipermeable membrane separating two solutions with different [more]Osmotic pressure - Community and Resources

Noun
1. (physical chemistry) the pressure exerted by a solution necessary to prevent osmosis into that solution when it is separated from the pure solvent by a semipermeable membrane
(hypernym) pressure, pressure level, force per unit area
(hyponym) hypertonicity
(classification) physical chemistry

Pressure which must be applied to a solution to prevent water from flowing in via a semipermeable membrane .