What will occur if solution A containing 400 mosmol/L nonpenetrating solute is separated by a biological membrane from solution B containing 600 mosmol/L nonpenetrating solute?

The volume of solution B will increase

Explanation:

If a solute is non-penetrating it means it cannot pass through a biological membrane. In this case we have two non-penetrating solutions with different osmolarity separated by biological membrane. Solvent from solution with lower osmolarity will tend to pass the membrane in order to equalize the solute concentrations on the two sides of the membrane. This process is called osmosis and it is spontaneous. Solvent moves through the membrane from a less concentrated solution (400 mosmol/L) into a more concentrated one (600 mosmol/L). Because of that, the volume of solution B will increase.