Tag: osmotic pressure


One must fully understand the history to appreciate today’s textbook thermodynamic theory of osmosis.

Endosmometer by Dutrochet

Nobel Lecture by Jacobus H. van’t Hoff

van’t Hoff Nobel prize for his work with osmotic pressure. The theory of Osmosis is not the theory of osmotic pressure.. See Atkins applied pressure to a vessel of water raises the vapor pressure..

Cell behavior in hypotonic / hypertonic solutions.

Our efforts to apply the vapor pressure theory of osmosis to medical physiology have been difficult.   The difficulty appears to be due to language differences. Therefore, we’re going to look at a very simple example from a popular medical text.   A cell is placed into pure water.  The osmolality of pure water is much ….  Read More

Osmosis in living organisms

Osmosis is the mechanism for transferring fluids and nutrients across membranes. It occurs in plants and animals and maintains the proper balance between extracellular and intracellular fluids.    Although osmotic pressure is measured in the laboratory and has been referred to as a driving force for osmosis     Osmotic pressure only occurs in laboratory experiments and calculations.  ….  Read More

Osmotic Pressure

OSMOTIC PRESSURE JA Nollet’s simple experiment (1748) to investigate the filter efficiency of a bladder membrane produced an enigma which is still misunderstood by many persons today.    Wine in a column was separated from pure water by a pig’s bladder membrane (figure 1).    The static pressure produced by a column of wine was expected to ….  Read More