Dilution 

• Dilution refers to the decrease in concentration of a particular solute in a solution. A solution is made up of a solvent that contains dissolved solutes. The term can be used to describe liquids as well as gasses. 
• A dilution is carried out by adding more solvent to a solution while keeping the solute content constant. A common example is that of an aqueous solution containing sodium chloride (NaCl). Adding more water to the solution dilutes the solution because the NaCl content is now spread over a greater volume. 
• Dilution is determined by the equation C1V1 = C2V2, where C1V1 refers to the initial concentration and initial volume while C2V2 refers to the final concentration and final volume of the solution. 

Dilution Factor 

• Dilution factor refers to a measure of dilution or the extent of the dilution. 
• Dilution factor is determined by dividing the final volume of the solution from the initial volume.
• Dilution factor is not expressed in units.