Osmosis

Theories on the Cause of Osmosis

A simple and appealing story for osmosis is the niggardliness of piss explanation--water in pure water is merely much concentrated than water in responses because the solute has to take up some room in the solution. According to this idea, water diffuses into a hyperosmotic solution because it is diffusing down its concentration gradient. As Weiss (1996) points out, this predicts water movement in the rightfulness direction, tho not of the right magnitude. Water movement in osmosis is faster than diffusion, and seems to be more like mass water movement caused by a pressure difference (Weiss, 1996, p. 218). Also, as Salisbury and Ross (1992, p. 39) point out, adding solutes to a solution decreases the concentration of water in most cases, but in some cases solutions have a higher concentration of water . The Handbook of Chemistry and Physics has a bulky section on solutions of common solutes, and it discloses that a 0.2 M solution of NaCl has a markedly higher water concentration (995 g/L) than a 0.2 M solution of sucrose (955 g/L) (Wolf et al., 1982, pp. D261 and D270). thus far our experiments will disclose that a potato cores loses water to a 0.2 M solution of NaCl but it gains water from a 0.2 M solution of sucrose. Also, if we compare 0.2 M solutions of sucrose and glucose, 0.



2 M glucose has a higher water concentration than 0.2 M sucrose (976 g/L vs. 955 g/L) (Wolf et al, 1982, p. D239) . This makes sense because the smaller glucose molecules take up less room in the solution. However, these two solutions have scarcely the same osmotic potential.

A slightly more thickening theory that is often found in general biology books (including your text, p. 117) is the bound water explanation. This says that any hydrophilic solute (like sucrose or NaCl) will bind up hydrating water and prevent it from wretched freely. Therefore, the brass of a semipermeable membrane with pure water has a higher free water concentration than the side with...If you want to get a full essay, order it on our website: Orderessay



If you want to get a full essay, wisit our page: write my essay .