The mechanism responsible for driving<unk>  has commonly been represented in biology and chemistry texts as either the dilution of water by solute (resulting in lower concentration of water on the higher solute concentration side of the membrane and therefore a diffusion of water along a concentration gradient) or by a solute's attraction to water (resulting in less free water on the higher solute concentration side of the membrane and therefore net movement of water toward the solute). Both of these notions have been conclusively refuted. The diffusion model of<unk>  is rendered untenable by the fact that<unk>  can drive water across a membrane toward a higher concentration of water. The "bound water" model is refuted by the fact that<unk>  is independent of the size of the solute molecules—a colligative property—or how hydrophilic they are. It is difficult to describe<unk>  without a mechanical or thermodynamic explanation, but essentially there is an interaction between the solute and water that counteracts the pressure that otherwise free solute molecules would exert. One fact to take note of is that heat from the surroundings is able to be converted into mechanical energy (water rising). Many thermodynamic explanations go into the concept of chemical potential and how the function of the water on the solution side differs from that of pure water due to the higher pressure and the presence of the solute counteracting such that the chemical potential remains unchanged. The virial theorem demonstrates that attraction between the molecules (water and solute) reduces the pressure, and thus the pressure exerted by water molecules on each other in solution is less than in pure water, allowing pure water to "force" the solution until the pressure reaches equilibrium.
Osmosis
Thickened fluids
Aqueous humour
Cosmesis
Blood volume
Cryosupernatant
Nitrate
Electricity