Relative osmotic pressure

Definition

Relative osmotic pressure is the pressure required to stop the net flow of solvent molecules through a semipermeable membrane when compared between two solutions. It reflects the difference in solute concentration across the membrane.

5 Must Know Facts For Your Next Test

1. Osmotic pressure depends on the solute concentration; higher solute concentrations result in higher osmotic pressures.
2. Relative osmotic pressure can be measured using van't Hoff's law: $\Pi = iMRT$, where $\Pi$ is osmotic pressure, $i$ is the ionization constant, $M$ is molarity, $R$ is the gas constant, and $T$ is temperature.
3. It plays a critical role in biological systems, helping to maintain proper cell function and volume.
4. In medical applications, relative osmotic pressure is crucial for processes like dialysis and intravenous fluid administration.
5. Differences in relative osmotic pressure can lead to osmosis, causing water to move from areas of low solute concentration to high solute concentration.

Review Questions

• How does relative osmotic pressure change with increasing solute concentration?
• What role does temperature play in calculating relative osmotic pressure using van't Hoff's law?
• Why is understanding relative osmotic pressure important for medical procedures like dialysis?

Related terms

Osmosis:

The movement of solvent molecules through a semipermeable membrane from a region of lower solute concentration to higher solute concentration.

Semipermeable Membrane:

A membrane that allows certain molecules or ions to pass through it by diffusion and occasionally specialized processes.

Van't Hoff's Law: $\Pi = iMRT$, an equation used to calculate the osmotic pressure of a solution based on its solute concentration and temperature.