A beaker of water is separated by a selectively permeable membrane that allows the passage of water but not ions. A. A solution of 4% sodium chloride (NaCl) is placed on one side of the membrane and pure water is placed on the other side of the membrane. B. The solutions are allowed to equilibrate. C. At this point, which process is going on? facilitated diffusion primary active transport secondary active transport osmosis

Osmosis.

Explanation:

If there is a selectively permeable membrane which is separating two liquids of different osmolarity or solute concentration then the process by which the solvent will move from one solution to another so as to attain equilibrium is known as osmosis. The existence of a selectively permeable membrane is the basic difference between diffusion and osmosis. Osmosis is characterized by the presence of such membrane which allows the movement of solvent only and restricts the movement of solute. In contrast to this, in diffusion there is no such restriction on the movement of particles from a region of high concentration to a region of low concentration.

In view of above in the given example, the solvent i.e. water will tend to move from pure water side towards the 4% NaCl solution side and the movement will continue until the osmolarity becomes equal on both the sides.