demonstrations:use_of_volumetric_pipette

Use of Volumetric Pipette

Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★★☆ Can be done by science teachers
Safety: ★☆☆ Minimal safety procedures required

Categories: Chemical Quantities and Calculations, Lab Skills and Safety, Measurement and Units

Alternative titles: Techniques for Accurate Liquid Transfer

Summary

Correct technique for using a glass volumetric pipette.

Procedure

  • Refer to links for correct use of the volumetric pipette.

Using a volumetric pipette correctly - Michael Seery:


The Volumetric Pipet and Pipetting Technique - NAIT Chemical Technology:


📄 Using Calibrated Glass Pipettes - Lisa Nichols: https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_Lab_Techniques_(Nichols)/07%3A_Technique_Summaries/7.02%3A_Using_Calibrated_Glass_Pipettes

Variations

None

Safety Precautions

  • Never pipette by mouth - always use a pipette bulb.
  • Avoid drawing liquid into the bulb to prevent contamination.
  • Handle glass pipettes carefully to prevent breakage and injury.
  • Dispose of pipettes properly if they become contaminated with hazardous solutions.

Questions to Consider

  • Why is it important not to blow out a TD pipette? (They are calibrated to deliver the correct volume without forcing out the last drop.)
  • What is the difference between a TD and a TC pipette? (TD delivers a specified volume, while TC is calibrated to contain a volume that must be completely expelled.)
  • Why should a pipette be conditioned with the reagent before use? (It prevents dilution or contamination from residual liquid inside the pipette.)
  • How can incorrect pipetting technique affect experimental results? (It can lead to inaccurate measurements and errors in solution concentration.)