Dilution Calculator

| Added in Chemistry

Understanding Dilution

Dilutions are used to reduce the concentration of a substance by adding more solvent. This is essential in laboratories for preparing solutions with precise concentrations for experiments, manufacturing, and research.

The Formula

The dilution formula is:

[M_{1} \times V_{1} = M_{2} \times V_{2}]

Where:

  • M₁ = Stock concentration (initial concentration)
  • V₁ = Volume of stock solution needed
  • M₂ = Final concentration (desired concentration)
  • V₂ = Final volume (total volume after dilution)

Solving for V₁ (volume of stock needed):

[V_{1} = \frac{M_{2} \times V_{2}}{M_{1}}]

Example Calculation

Problem: You have a 5 M stock solution and want to prepare 200 mL of a 1 M solution. How much stock solution do you need?

Given:

  • Stock concentration (M₁) = 5 M
  • Final concentration (M₂) = 1 M
  • Final volume (V₂) = 200 mL

Solution:

[V_{1} = \frac{1 \times 200}{5} = 40 \text{ mL}]

You need 40 mL of the 5 M stock solution. Then add solvent (water) to bring the total volume to 200 mL.

Summary Table

Stock Concentration (M) Final Concentration (M) Final Volume (mL) Required Stock Volume (mL)
5 1 200 40

Applications

  • Preparing laboratory reagents
  • Pharmaceutical formulations
  • Industrial chemical processing
  • Research and experiments
  • Quality control testing

Frequently Asked Questions

The dilution formula is M1 × V1 = M2 × V2, where M1 is stock concentration, V1 is volume of stock needed, M2 is final concentration, and V2 is final volume. Solving for V1 gives V1 = (M2 × V2) / M1.

Take the calculated volume of stock solution and add solvent (usually water) until you reach the desired final volume.

Use Molar (M) for concentrations and milliliters (mL) for volumes. Ensure all inputs use consistent units for accurate results.

If the required stock volume exceeds the final volume, your desired concentration is higher than your stock concentration. You cannot dilute to a higher concentration.