Using a Burette
Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required
Categories: Chemical Quantities and Calculations, Lab Skills and Safety, Measurement and Units
Alternative titles: Burette Technique for Liquid Measurement
Summary
A buret is a precise laboratory instrument used to deliver measured volumes of liquid. By reading the initial and final liquid levels, the exact volume dispensed can be calculated to a high degree of accuracy.
Procedure
- Rinse the burette 2–3 times with the liquid you intend to use, rotating it to coat all interior surfaces; drain through the stopcock into waste.
- Clamp the burette securely to a ring stand using a burette clamp.
- Fill the burette with the liquid; note the starting volume (not necessarily at 0.00 ml). Use a sheet of white paper behind the burette to aid reading.
- Open the stopcock slowly to allow the liquid to drain into the receiving vessel.
- Once the desired amount is dispensed, close the stopcock and touch the burette tip to the vessel wall to remove any drops.
- Record the final burette reading.
- Calculate the delivered volume by subtracting the initial reading from the final reading. Example: 24.34 ml – 21.36 ml = 2.98 ml delivered.
- Drain any remaining liquid and rinse the burette with water before storage.
Links
How to use a burette - ISU Gen Chem Lab Tutorials:
How to Use a Buret - Supreme Science:
📄 Using a Buret - Harper College: https://dept.harpercollege.edu/chemistry/chm/100/dgodambe/thedisk/labtech/burtech.htm
Variations
- Use different sizes of burets (5 ml, 25 ml, 50 ml, 100 ml) depending on the accuracy required.
Safety Precautions
- Always wear safety goggles and a lab coat when handling chemicals.
- Ensure the burette is securely clamped to prevent tipping or spilling.
- Dispose of waste liquids properly; never return them to stock bottles.
- Rinse thoroughly with water after use to prevent chemical residue buildup.
Questions to Consider
- Why is it important to rinse the burette with the solution to be used rather than water? (It prevents dilution of the solution and ensures accuracy.)
- Why are burette markings reversed compared to a graduated cylinder? (Burets measure the amount delivered, so volume decreases as liquid is dispensed.)
- How do you minimize reading errors when recording burette volumes? (Use a white background, read at eye level at the bottom of the meniscus, and avoid parallax error.)