Accurate Dilution of Stock Solutions

Accurate Dilution of Stock Solutions

Section 1: Basics of Dilution

  • Dilution is the process of decreasing the concentration of a solute in a solution, usually by mixing with more of the solvent.
  • Stock solutions are concentrated solutions that are intended to be diluted to lower concentrations for use in various experiments.
  • A solution’s concentration refers to the amount of solute dissolved in a specified amount of solvent.

Section 2: Process of Dilution

  • To dilute a stock solution, measure out a certain volume of the stock and add it to a new container.
  • Then add solvent to the new container to increase its volume, thereby reducing the concentration of the solution.
  • The ratio of the volume of stock solution used to the total volume desired determines the dilution factor.

Section 3: Calculations Involving Dilution

  • The relationship between initial and final concentrations and volumes is described by the dilution equation, C1V1 = C2V2 , where:
    • C1 and V1 are the concentration and volume of the stock solution respectively
    • C2 and V2 are the concentration and volume of the diluted solution respectively
  • Use this equation to calculate any one variable when the other three are known.

Section 4: Accurate Dilution Techniques

  • Pipettes and graduated cylinders are usually used to measure the volume of stock solution and solvent due to their high accuracy.
  • Always make sure that the markings on the measuring equipment are read at eye level to reduce error.
  • When adding solvent to the stock solution, pour slowly to avoid overshooting the desired volume.
  • Make sure you mix the solution well after adding solvent to ensure equal distribution of the solute throughout the solution.

Section 5: Safety Precactions in Dilution Process

  • Always wear appropriate personal protective equipment like lab coats, gloves, and safety goggles while performing a dilution.
  • If you are diluting a hazardous solution, make sure to work in a well-ventilated area or under a fume hood.
  • Dispose of all materials properly after you complete your dilution to ensure a safe work area.