The pressure that results from solvent flow in osmosis is called

• A. Equilibrium
• B. Phase
• C. Phase Diagram
• D. Osmotic Pressure

Answer: (D)

Osmotic pressure is the pressure that arises when solvent flows through a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration. As water moves, it creates a hydrostatic pressure on the side with the solute, opposing further flow. The pressure exactly required to stop the net movement is osmotic pressure. This pressure depends on solute concentration, temperature, and the number of dissolved particles; for dilute ideal solutions, π = iCRT. Equilibrium is reached when the external pressure balances this osmotic pressure. The other terms describe states of matter and their transitions, not the pressure generated by solvent movement in osmosis.