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I am a high school student and I am very confused in how we define osmotic pressure? Osmotic pressure is defined as the pressure required to stop the diffusion of solvent into a solution by applying external pressure over solution, which means that when the pure solvent is diffusing into the solution then it will apply pressure on the semi permeable membrane and when we have applied the same external pressure over the solution then there is no net movement of solvent occurs across the membrane and mathematically it is equal to P=cRT, where c is the concentration of solution , T is temperature in kelvin and R is the universal gas constant, if we go by this equation and calculate the osmotic pressure of 1 molar concentrated solution at room temperature it comes out to be almost 2495Pa which means 2495Newton/m^2 which is very high pressure and it doesn't seem to be true as osmosis is very slow process it surely cannot generate that much of pressure( just to imagine how large is that pressure assume an area of 1m^2 and place Mass of 249.5kg on it), so I think that it should not be that higher, so ,I am unable to understand what is actually osmotic pressure ,on which does it actually act and how do we actually calculate it?

we say that when a cell is placed in hypotonic solution then osmotic pressure is greater than Turgor pressure and water will flow inside the cell, but I have a confusion that like turgor pressure acts on the wall of cell ,osmotic pressure should also act on the wall and in opposite direction of turgor pressure, so by this logic wall should compress more as osmotic pressure on it will cause it to compress and turgor pressure will cause it to expand but Osmotic pressure is greater than turgor pressure it should compress, but it doesn't happen? we only talk of turgor pressure to explain the expansion but not osmotic pressure why? I know I am going wrong somewhere if Osmotic pressure would really leads the cell to compress then an animal cell would have never burst in hypotonic solution. and if osmotic pressure is also acting on the wall or membrane then net pressure on the wall is O.P-T.P (in inward direction) , and not only T.P (outward) so the wall pressure here also should not be same as turgor pressure?

If anyone will explain me this by giving as many examples as possible than it would be very helpful for me to understand because its my first time I came to know about these things.

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when we talk about external force applied in this case we talk about a setup that is made by us. like a U tube experiment that is filled with water and separates both the hands of the tube via semipermiable membrane and we add solute one side and due to this water starts to rise in that hand of the tube to avoid this rise in water level an external pressure is applied tht prevents this water rise and this pressure is termed as osmotic pressure. THIS IS THE CASE OF A ENVIROMENT WHERE EXTERNALFORCES CAN BE APPLIED BY US AND IT IS VERY MUCH DIFFERENT FROM THAT OF THE CELL WORLD. in case of cells osmotic pressure is directly proportional to the concentration of the solution i.e more the solute more the OP and visa versa. in cells osmotic pressure are internal force that is caused due to difference in concentration of the solutions. and as we know water move from low osmotic pressure to high osmotic pressure { from less concentrated to more concentrated solution} thus cell swells up because of entering of water when cell is placed in pure water or hypotonic solution.

CONCLUSION : CELL DO NOT SHRINK BECAUSE NO EXTERNAL FORCE IS APPLIED BY US THE DEFINATION U GAVE IS CORRECT BUT IT IS NOT APPLIED IN CELL WORLD. IN CELL WORLD OP IS A PRESSURE DEVELOPED DUE TO DIFFERENCE IN CONCENTRATION OF SOLUTIONS AND THIS PRESSURE IS CREATED INORDER TO EQUAL THE CONCENTRATION OF SOLVENT (WATER) IN BOTH THE SOLUTIONS.

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