Dilution - Dilutions of Solutions - Definition & Meaning, Formula, Methods & Importance of Dilution (2024)

What is Dilution?

Dilution is the process of “lowering the concentration of a solute in a solution by simply adding more solvent to the solution, such as water.” Diluting a solution entails adding more solvent without adding more solute.

Taking a higher concentration solution and adding water until the required concentration is reached is a popular way of creating a solution of a specific concentration. Dilution is the term for this procedure. Dilution can also be accomplished by mixing a higher-concentration solution with a lower-concentration solution. Because stock solutions are frequently acquired and stored in highly concentrated quantities, diluting solutions is a required operation in the laboratory. The solutions must be accurately diluted to a known, lower concentration before being used in the lab.

Table of Contents

• Dilution Formula
• Dilution Method
  • Simple Dilution Method
  • Serial Dilution Method
• Importance of Dilution
• Frequently Asked Questions – FAQs

Dilution Formula

Dilution is the process of adding a solvent to a solution to reduce the concentration of the solute. Concentration is the process of removing solvent from a solution in order to raise the concentration of the solute in the solution.

The amount of solute remains constant in both dilution and concentration. This allows us to compute the new solution volume required for the desired solute concentration. Using the notion of molarity as a reference.

Molarity = moles of solute / liters of solution

Moles of solute = (molarity)(liters of solution)

moles of solute = MV

Because this quantity does not change before or after a concentration change, the product MV must be the same before and after the change in concentration. The initial and final conditions are represented by numbers.

M₁V₁ = M₂V₂

as if it were a dilution equation The volumes must have the same units of measurement. It’s worth noting that this equation only offers the beginning and final conditions, not the change’s magnitude. Subtraction is used to calculate the amount of change.

Removing the solvent from a solution is part of the concentration process. Typically, this is accomplished by evaporating or boiling, with the assumption that the heat of boiling has no effect on the solute. In these cases, too, the dilution equation is applied.

Dilution Method

1. Simple Dilution Method

To obtain the desired concentration, a simple dilution is one in which a unit volume of a liquid material of interest is blended with an adequate volume of a solvent liquid. The total number of unit volumes in which the material will be dissolved is the dilution factor. To get the real dilution, the diluted material must be completely combined.

A 1:5 dilution (also known as a “1 to 5” dilution) involves mixing 1 unit volume of solute (the item to be diluted) with 4 unit volume of solvent medium (therefore, 1 + 4 = 5 = dilution factor).

A dilution factor of 5 is obtained by diluting frozen orange juice concentrate with four extra cans of cold water (the dilution solvent), i.e., the orange concentrate represents one unit volume to which four additional cans (identical unit volumes) of water have been added. As a result, the orange concentrate is now dispersed throughout 5 unit volumes. This is referred to as a 1:5 dilution and is now 1/5 as concentrated as before.

2. Serial Dilution Method

Diluting a stock or standard solution many times in succession is known as serial dilution. For each dilution, the dilution factor is usually kept constant, resulting in an exponential drop in concentration. Serial dilutions are used to make extremely diluted solutions as well as solutions for studies requiring an exponential or logarithmic concentration curve. In experimental sciences such as biochemistry, pharmacology, microbiology, and physics, serial dilutions are commonly utilised.

A serial dilution is a series of dilutions used to reduce a dense cell culture to a more acceptable concentration. Each dilution lowers the bacterium concentration by a certain amount. It is possible to determine how many germs started with by calculating the overall dilution for the entire series.

The dilution factor or the dilution is the initial volume divided by the final volume.

DF = Vi / Vf

Importance of Dilution

• A dilution can be used to not only lower the concentration of the analyte being tested so that it is below acceptable limits but also to help minimize interferences from other compounds in the sample that could artificially change the analysis.
• Dilution is the process of weakening or deconcentrating a solution. Serial dilutions are used in microbiology to reduce bacterial concentrations to the required concentration for a particular test method or to a concentration that is easier to count when plated to an agar plate.
• Serial dilution provides a number of advantages, including the fact that the materials required are usually already in the lab and don’t require any new engineering. As the experiment develops, the conditions can be tweaked.
• Serial dilutions are most commonly employed in serological processes, where technicians must dilute serum to find the smallest concentration that still produces a reaction.