What is the end result of osmosis when the system reaches equilibrium?

When osmosis occurs, it involves the movement of water across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration. The process continues until the concentrations of solute on both sides of the membrane become equal, achieving a state known as equilibrium. At this point, there is no net movement of water across the membrane, and the concentrations of solute on both sides are balanced.

Achieving equal concentrations means that the water molecules have moved to a point where they have compensated for the difference in solute concentrations, resulting in a stable state. Therefore, the correct answer effectively illustrates the primary goal of osmosis, which is the equalization of solute concentrations across a barrier.

The other options do not accurately describe the outcome of osmosis at equilibrium. For instance, maximum pressure on the semi-permeable membrane can occur during the process but is not the defining characteristic of the equilibrium state. Similarly, increased volume on one side may occur initially as water moves to balance concentrations, but this does not represent the final state once equilibrium is reached. Finally, separation of solutes into distinct layers does not characterize equilibrium in osmosis; rather, equilibrium suggests a uniform distribution of solutes.