Question

A dialysis membrane is a barrier between solution A (0.5M NaCl) and solution B (0.5M Sucrose). The membrane is permeable to NaCl, Sucrose, and Water. What is the initial reaction of the NaCl, Sucrose, and Water?

Answer 1

Solution A = 0.5 M NaCl
NaCl ---> Na+ + Cl-
Osmolarity = 1.0 Osm

Solution B = 0.5 M Sucrose
Sucrose is a non-ionizable solute
Osmolarity = 0.5 Osm

It is given that the membrane is permeable to water, NaCl, and sucrose.

Water moves from high water potential to low water potential.
Water moves from hypotonic solution to hypertonic solution.

Solutes also move from high chemical potential (Osmotic potential) to low osmotic potential.

Solution A = Hypertonic
Solution B = Hypotonic

Water moves from B to A.
NaCl moves from A to B.