Question

the membrane in this u - shaped tube is not permeable to the solute, but it is permeable to water. so diffusion of solute molecules will not occur, but osmosis will. which model shows how the water in the u - shaped tube will move over time?

Explanation:

1. Recall the concept of osmosis: water moves from an area of lower solute concentration (higher water potential) to an area of higher solute concentration (lower water potential) across a semipermeable membrane.
2. In the initial U - tube, the right side has more solute particles (orange dots) than the left side. So, water will move from the left (lower solute concentration) to the right (higher solute concentration) via osmosis.
3. Analyze the options:

• The left - most graph shows water moving to the left, which is incorrect as solute is more on the right.
• The middle graph shows the water level on the right side higher (because water moved to the right) and the solute particles distributed such that the right side still has a relatively higher solute concentration (more solute particles per unit volume, considering the increased water volume), which is consistent with osmosis.
• The right - most graph shows equal water levels, which would imply no net movement of water, but since the solute concentrations were initially unequal, this is incorrect.

Answer:

The Middle Graph