Problem B (SW) What Osmotic Pressure (Pi) can be generated by a 2M sugar solution at 16oC. (hint) use Pi = MRT change 16oC to K R = .08 L Atm/mol K

Question

 

Problem B (SW) What Osmotic Pressure (Pi) can be generated by a 2M sugar solution at 16oC.

(hint) use   Pi = MRT    change 16oC to K    R = .08 L Atm/mol K



Your answer should be greater that 1 ATM.. a pressure that causes the seed to burst!

Answer 1

This seems like a misunderstanding of how osmotic pressure works. If you had a 2M sugar solution with a semipermeable membrane and water on the other side, the osmotic pressure of the water trying to push into the concentrated solution would be π = CRT where C is concentration in molarity, R is .0821 l-atm/mole-K, T is the temperature in Kelvin (273 + °C), and π is the osmotic pressure in atmospheres.

You can just jam the values into the equation and do the multiplication ( I get 47 atm)

If the seed is filled with pure water, then that is the pressure pushing the water out which will shrivel the seed.

If the seed is filled with the 2M solution, then water will push in and expand the seed with enormous pressure.