Problem 11 - Biology: The Unity and Diversity of Life

Question

Solutes tend to diffuse from a region where they are ____(more/less) concentrated to another where they are _____(more/less) concentrated.

Step-by-Step Solution

Answer

more, less.

Step 1: Identify Key Concept

Understand that this exercise is about diffusion, a process where particles move from an area of higher concentration to an area of lower concentration.

Step 2: Analyze the Question Structure

Notice that there are two blanks to fill in the sentence: "Solutes tend to diffuse from a region where they are ____(more/less) concentrated to another where they are _____(more/less) concentrated." This suggests we need to fill in terms that represent the movement from regions of different concentrations.

Step 3: Apply Diffusion Principles

According to the principles of diffusion, solutes move from an area of high concentration to an area of low concentration. Thus, the blanks should be filled accordingly.

Step 4: Formulate the Answer

Fill in the blanks with the terms identified using the diffusion principle. The sentence becomes: "Solutes tend to diffuse from a region where they are more concentrated to another where they are less concentrated."

Key Concepts

Understanding Solute Concentration

Solute concentration refers to the amount of solute present in a given volume of solvent. Solutes are the substances that are dissolved in a solvent to form a solution.
The concentration of solute influences how the solution behaves and interacts with other solutions. For example, a sugar solution has sugar as the solute and water as the solvent. The sweetness level depends on the concentration of the sugar.

• Concentration is typically expressed in terms such as molarity, which reflects moles of solute per liter of solution.
• A higher solute concentration means more solute particles in the same amount of solvent.
• A lower concentration means fewer solute particles.

If you imagine adding more sugar to a cup of tea, you are effectively increasing the solute concentration.
This increased concentration can affect properties like taste, boiling point, and even freezing point. Understanding solute concentration is integral to grasping how diffusion works, since diffusion aims to balance out differences in solute concentrations across regions.

What is Higher Concentration?

Higher concentration occurs when there are more solute particles present in a given volume of solvent compared to another region. This creates a region where particles are more densely packed.

• Imagine a nectar solution with more sugar particles squeezed into the same volume of water. This would be a higher concentration compared to a diluted nectar.
• In the context of diffusion, regions with higher concentration have particles that are more likely to "spread out."
  They do this to reach an equilibrium with adjacent lower concentration areas.
• Higher concentration is the starting point for diffusion, as particles naturally move to where they are less concentrated.

It's like crowding a room; many people will eventually move to a room with more space and less crowding.
This analogy helps visualize how higher concentration serves as the source in diffusion processes.

Defining Lower Concentration

Lower concentration is when there are fewer solute particles within the same volume of solvent compared to another region. This means there are more spaces between solute particles.

• For instance, consider a lightly sweetened lemonade compared to a sugar-syrup lemonade. The former has a lower concentration of sugar.
• In diffusion, the movement of particles aims to achieve equality. Particles move from an area of higher concentration to fill an area of lower concentration.
• This concept of seeking equilibrium through movement from high to low concentration is a foundational principle of diffusion.

Just like how the sweet aroma of a flower fills a room starting from the point of origin outward, diffusion helps balance concentrations.
Areas of lower concentration act as receptors, absorbing particles to reach an even distribution.