Question

What quantity remains constant when you dilute a solution?

Short answer

The number of moles of solute remains constant during dilution.

Step-by-step solution

Understanding Dilution

When diluting a solution, you add more solvent to a solution without adding more solute. This process changes the concentration but not the amount of solute in the solution.

Identify the Key Concept

The key concept in dilution is that the number of moles of solute remains constant. This means that although the volume and concentration change, the total amount of solute does not.

The Formula Behind Dilution

The formula for dilution is \( C_1V_1 = C_2V_2 \), where \( C_1 \) and \( C_2 \) are the initial and final concentrations, and \( V_1 \) and \( V_2 \) are the initial and final volumes, respectively. This equation expresses the constancy of the number of moles of solute, as \( C_1V_1 = C_2V_2 \) implies that the initial and final moles are equivalent.

Conclusion

From the equation \( C_1V_1 = C_2V_2 \), it is clear that what remains constant is the number of moles of solute, since both sides of the equation represent it.

Key concepts

Understanding the Concentration of Solutions

The concentration of a solution refers to the amount of solute that is dissolved in a given quantity of solvent. It tells us how strong or weak a solution is. Concentration is usually expressed in terms of molarity, which is the number of moles of solute per liter of solution. This can be represented by the formula:

• Molarity (M) = Moles of solute / Volume of solution (L)

Dilution affects concentration because it involves adding more solvent to a solution. When you dilute a solution, although the volume of the solution increases, the amount of solute remains the same since no additional solute is added. Therefore, the concentration of the solution decreases as its volume increases. This principle is crucial to understanding various chemical reactions and processes, especially when precise concentrations are necessary for experiments or industrial purposes.
Remember that the main goal of dilution is to achieve a desired concentration for a particular application, while keeping the moles of solute constant.

Exploring the Concept of Moles of Solute

In chemistry, the mole is a fundamental concept used to quantify the amount of a substance. A mole represents Avogadro's number (\(6.022 \times 10^{23}\)) of particles, which can be atoms, molecules, or ions. When we talk about moles of solute in a solution, we refer to the number of moles of the dissolved substances in the solvent. This remains constant during dilution, which is a key element of the exercise.
Despite any changes in the concentration or volume of the solution, the number of moles of solute always remains the same after dilution. This property is often utilized to determine how solutions will behave when diluted or concentrated. For instance, a scientist can predict how much of a solution is needed to reach a particular concentration without altering the total amount of solute.
This constancy is what allows us to utilize formulas like the dilution equation (\(C_1V_1 = C_2V_2\)) effectively, ensuring the total moles of solute are the same before and after dilution.

Utilizing Chemistry Equations in Dilution

Chemistry equations are essential tools for understanding and predicting the behavior of chemical substances, particularly in processes like dilution. The dilution equation (\(C_1V_1 = C_2V_2\)) is a vital equation in chemistry that links the initial and final concentrations and volumes of a solution. Each part of this equation provides meaningful insights:

• \(C_1, V_1\) are the initial concentration and volume.
• \(C_2, V_2\) are the final concentration and volume after dilution.

This equation highlights that, while the concentration and volume may vary, the product of concentration and volume will always equal the initial moles of solute, which remain unchanged. This understanding allows chemists to carefully prepare solutions of desired concentrations by knowing precisely how much solvent to add without changing the solute quantity.
Utilizing such chemistry equations effectively requires a good grasp of the underlying concepts they represent. This includes understanding what each variable signifies and how changes in one affect the others. Comprehending these relationships streamlines many experimental procedures in both educational and industrial settings, ensuring precision and accuracy.