Question

In osmosis, when will there be changes in volume of the two compartments separated by a selectively permeable membrane?

	A.	When particles in solution are prevented from crossing the membrane (nonpenetrating solutes).
	B.	When the water concentrations on both sides of the compartments are the same.
	C.	When particles in solution can diffuse across the membrane along with water.
	D.	When the solutes concentration on both sides of the compartments are the same.

Answer 1

Osmosis is a process in which the solvent molecules move from a region of lower solute concentration to a region of higher solute concentration through a semipermeable membrane.

The changes in the volume of the two compartments will be:

A. When the solute particles in a solution are prevented from crossing the membrane (nonpenetrating solutes), then the concentrations in the two compartments differ. So, the solvent moves from one compartment to another (from lower compartment of lower solute concentration to higher) This will bring change in the volume of two compartments.

The changes in the volume of two compartments do not occur in the following cases (the reasons being):

B. When the water concentration on both sides is the same, there will be no movement of water as concentration is the same so, no volume change(no osmosis).

C. When particles in the solution diffuse (penetrating solutes) the concentration in both the compartments remains the same so, no solvent movement thus no volume change.

D. When the concentration of solute is the same there is no concentration gradient to cause the movement of solvent therefore volume change is not possible.