Question

A can of frozen lemonade calls for the addition of three cans of water to make a pitcher of the beverage. Why is this a dilution?

Short answer

Adding three cans of water to the frozen lemonade concentrate reduces its concentration, making it a dilution.

Step-by-step solution

Understanding the Concept of Dilution

Dilution is the process of reducing the concentration of a solute in a solution, usually by adding more solvent. In this exercise, consider the frozen lemonade as the solute and the water as the solvent.

Identify the Original Mixture

The original mixture is the can of frozen lemonade concentrate before any water has been added. This concentrate is highly concentrated with flavor and sweetness.

Adding Solvent to the Mixture

According to the exercise, three cans of water are added to the can of frozen lemonade concentrate. This increases the total volume of the mixture while maintaining the same amount of lemonade concentrate.

Resultant Beverage

After adding the three cans of water, the concentration of the lemonade in the beverage is lower because it is now spread out in a larger volume of liquid.

Conclusion

Therefore, adding the water to the frozen lemonade concentrate decreases its concentration, which is the definition of dilution.

Key concepts

Solute

In the context of our lemonade exercise, the solute is the frozen lemonade concentrate. The term 'solute' refers to the substance that is dissolved in a solvent to form a solution. Here, the concentrated lemonade is rich in flavor and sweetness.
When dealing with solutions, the solute is typically the component present in a smaller amount. For instance:

• Frozen lemonade in the can is the solute since it needs to be mixed with water.
• Solutes can be solids, liquids, or gases.

In most cases, the solute's concentration is what we alter through processes like dilution to fit our needs, whether that be making lemonade more palatable or preparing a less intense cleaning solution.

Solvent

The solvent in our lemonade example is water. The solvent is the component that dissolves the solute, resulting in a solution. Water is often called the 'universal solvent' because it can dissolve many different substances.
Some key points about solvents include:

• They are usually present in larger amounts compared to solutes.
• In the context of beverages, the solvent often makes up most of the final volume.

For frozen lemonade, you add three cans of water (solvent) to one can of concentrate (solute), leading to a well-mixed pitcher of lemonade.

Concentration Reduction

Concentration reduction is the process where the amount of solute per unit volume of solution decreases. This is exactly what happens during the dilution process.
Using the lemonade exercise, when three cans of water are added to one can of lemonade concentrate:

• The overall volume increases, but the amount of solute remains constant.
• The concentration of the lemonade decreases, making the taste less intense and more drinkable.

A dilute solution has a lower concentration of solute compared to a concentrated solution, which is more intense in flavor and sweetness.

Volume Increase

Volume increase occurs when additional solvent is added to a solution, which consequently leads to a decrease in the solution's concentration. In our lemonade scenario, adding three cans of water increases the total volume from one can to four cans.
Key points to remember about volume increase include:

• It doesn't change the amount of solute—in our case, the amount of lemonade concentrate stays the same.
• The volume increase results in a lower concentration of the solute in the solution.

This is why after adding water, you end up with a larger volume of a beverage that's less concentrated, which is the essence of dilution.