Difference Between Dilution and Dilution Factor

Key Difference – Dilution vs Dilution Factor
 

Dilution and dilution factor are common terms used for calculations in analytical chemistry. Dilution refers to the decrease of the concentration of a particular solute in a solution. This term can be used to describe both liquids and gases. Dilution factor is a measure of dilution; it describes the extent of the dilution. The key difference between dilution and dilution factor is that dilution of a solution is the decrease of the concentration of solutes in that solution whereas dilution factor is the ratio between the final volume and the initial volume of the solution.

CONTENTS

1. Overview and Key Difference
2. What is Dilution
3. What is Dilution Factor
4. Side by Side Comparison – Dilution vs Dilution Factor in Tabular Form
5. Summary

What is Dilution?

Dilution of a solution is the decrease of the concentration of solutes in that solution. A solution is composed of a solvent that has dissolved solutes in it. The concentration of these solutes is given as molarity or molality. Molarity is the amount of solutes present in a unit volume of solution (given by the unit mol/L). Molality is the mass of solute present in a unit volume (given by the unit kg/L). When the concentration of the solute in this solution is decreased, it is called a diluted solution.

A dilution is done by simply adding more solvent to the solution, holding the solute content a constant. For example, an aqueous solution containing sodium chloride (NaCl) can be diluted by adding more water. If the solute is a colored compound, the color of the solution fades when the solution becomes diluted.

Final Concentration Calculation

The final concentration of the solution can be determined using the following relationship.

C1V1    =    C2V2

C1 is the initial concentration

V1 is the initial volume

C2 is the final concentration

V2 is the final volume of the solution.

Ex: An aqueous solution of KCl contains 2.0 moles of KCl in 0.2 L of water. What would be the final concentration of the KCl solution if water (400 mL) is added?

Initial concentration of KCl (C1)     = 2.0 mol/0.2L  = 10 mol/L

Initial volume of the solution (V1)  = 0.2 L

Final volume of the solution (V2)   = 0.2 L + 0.4 L   = 0.6 L

Final concentration of solution (C2) can be determined using:

C1V1 = C2V2

10 mol/L x 0.2 L    = C2 x 0.6 L

C2 = 2 mol / 0.6 L = 3.33 mol/L

What is Dilution Factor?

Dilution factor (also known as the dilution ratio) is the ratio between final volume and initial volume of the solution. The final volume is the volume of the solution after dilution. Initial volume is the volume of solution before dilutes, or the volume of original solution used for the dilution. This relationship can also be used along with the mass of the solute.

Dilution Factor Calculation

Dilution factor = final volume (V2) / initial volume (V1)

Ex: Dilution of 200 mL of KMnO₄ aqueous solution by adding 200mL of water,

Dilution factor = (200mL + 200mL) / 200mL

= 400 mL /200mL

= 2

The above diagram shows a graph from a research in which the death of frogs is calculated along with the dilution of the pesticides added to an ecosystem.

What is the Difference Between Dilution and Dilution Factor?

Summary – Dilution vs Dilution Factor

Dilution and dilution factor are very common terms in chemistry. Dilution factor is the measure of dilution. The key difference between dilution and dilution factor is that dilution of a solution is the decrease of the concentration of solutes in that solution whereas dilution factor is the ratio between final volume and initial volume of the solution.

Reference:

1. “Dilution (Equation).” Wikipedia, Wikimedia Foundation, 12 Feb. 2018, Available here.
2. “Dilutions: Explanations and Examples.” Quansys Biosciences, Available here.

Image Courtesy:

1. “Diffusion Dilution” by Tess Watson (CC BY 2.0) via Flickr
2. “Figure 1 Xenopus Laevis” By Krmeyer0717 – Own work (CC BY-SA 4.0) via Commons Wikimedia