Question

A 10% glucose solution is placed in the thistle tube. The thistle tube is placed in a beaker that contains a 5% glucose solution. There is a differentially permeable membrane across the broad end of the tube, which is permeable to water but not to the sugar glucose. What will occur over time to the water? To the solute?

Answer 1

Answer:

The thistle tube has 10% glucose solution and it is placed in a beaker containing 5% glucose solution. Since the concentration of solution is higher in the tube, it is hypertonic compared to the outside solution. The membrane is permeable to water but not to glucose molecules so the process of osmosis can take place. Osmosis is the movement of solvent molecules from less concentrated to high concentrated solution. Here, the outside solution has lower concentration of glucose so water will move from here to the tube. Eventually, solute concentration will start to decrease inside the tube. Net movement of water will become zero when the two solutions become isotonic i.e. there is no difference in concentration between them.

Answer 2

The solution in the tube has a higher concentration of solute than the solution in the beaker. It is, therefore, hypertonic.