Dilution factor is the?

1. Analyze the question The question asks for the definition of "dilution factor" in volumetric analysis and solution preparation.

2. Explain the concept When you dilute a concentrated solution (stock) by adding solvent (distilled water), the amount of solute stays the same, but the total volume increases and the concentration falls.

The dilution factor tells you how many times the solution has been diluted:

Dilution factor (DF) = Final volume (dilute solution) ÷ Initial volume (concentrated solution)

It is also equal to:

DF = Concentration of stock ÷ Concentration of dilute solution

This follows from the dilution equation: C₁V₁ = C₂V₂, so V₂/V₁ = C₁/C₂.

3. Work through the options

• A. The amount of water added is just the volume of diluent. It is not a factor, which is a ratio or number of times.
• B. This is a quantity of water per 1 dm³, which is a volume rather than a ratio. It is not the definition.
• C. The number of times the volume of the concentrated solution is diluted to give the dilute solution. This matches DF = V₂/V₁, a pure number, so it fits.
• D. This describes the act of dilution, not a factor.

Example: If 10 cm³ of stock is diluted to 100 cm³, DF = 100/10 = 10. The solution has been diluted 10 times, and its concentration is 1/10 of the original.

4. Answer

5. Exam tip The word "factor" means a multiplier or a ratio, so look for the option that says "number of times". A factor is never an "amount" or an "act".