Question

Two solutions, a \(0.1 \%(\mathrm{~m} / \mathrm{v})\) albumin solution and a \(2 \%\) \((\mathrm{m} / \mathrm{v})\) albumin solution, are separated by a semipermeable membrane. (Albumin is a colloid.) a. Which compartment has the higher osmotic pressure? b. In which direction will water flow initially? c. In which compartment will the volume level rise?

Short answer

a. The compartment with 2% albumin. b. Water will flow from the 0.1% compartment to the 2% compartment. c. The volume level will rise in the 2% compartment.

Step-by-step solution

Understand Osmotic Pressure

Osmotic pressure is the pressure required to stop the flow of water across a semipermeable membrane. It depends on the concentration of solutes in the solution. A higher concentration of solutes results in higher osmotic pressure.

Determine Higher Osmotic Pressure (Part a)

Compare the concentrations of the two solutions: The first solution has a concentration of 0.1% (m/v) albumin. The second solution has a concentration of 2% (m/v) albumin.Since 2% > 0.1%, the second solution has the higher osmotic pressure.

Direction of Water Flow (Part b)

Water flows from the compartment with lower osmotic pressure (lower solute concentration) to the compartment with higher osmotic pressure (higher solute concentration) to try to equalize the concentration.Since the first solution (0.1%) has lower osmotic pressure than the second solution (2%), water will flow from the first solution to the second solution.

Determine Volume Change (Part c)

The volume level will rise in the compartment that is gaining water. Since water flows from the first solution (0.1%) to the second solution (2%), the volume level will rise in the compartment with the second solution (2%).

Key concepts

Semipermeable Membrane

A semipermeable membrane is a barrier that allows certain molecules, such as water, to pass through while blocking others, like solute particles.

This selective permeability is crucial in many biological and chemical processes. It helps control the movement of substances between two compartments.

For example, if you have two solutions separated by a semipermeable membrane, the membrane will allow water to move between the solutions, but it will not let larger molecules like albumin pass.

This characteristic is essential for the concept of osmotic pressure and the direction of water flow across the membrane.

Flow of Water

Water flows from an area of lower solute concentration to an area of higher solute concentration. This movement aims to equalize the concentration of solutes on both sides of the semipermeable membrane.

The key driving force behind this movement is osmotic pressure, which depends on the solute concentration in each compartment.

Let's take two compartments separated by a semipermeable membrane: one with 0.1% albumin and the other with 2% albumin.

• Water will flow from the 0.1% albumin compartment to the 2% albumin compartment.
• This movement continues until the solute concentrations on both sides reach equilibrium or are balanced.

Understanding how water flows based on solute concentration is crucial for predicting changes in volume and pressure.

Solute Concentration

Solute concentration refers to the amount of solute present in a given volume of solution. It's typically expressed as a percentage or in units like molarity.

Higher solute concentrations lead to higher osmotic pressure. This is because more solute particles increase the tendency of water to move across a semipermeable membrane to dilute the solute concentration.

In the exercise example, there are two solutions:

• The first with 0.1% (m/v) albumin.
• The second with 2% (m/v) albumin.

Since 2% is greater than 0.1%, the second solution has a higher solute concentration and thus higher osmotic pressure.

Understanding solute concentration helps us determine which way water will flow and where the volume will rise, making it a key concept in discussing osmotic pressure.