diagram of modern burette

A burette (also buret) is a vertical cylindrical piece of laboratory glassware with a volumetric graduation on its full length and a precision tap, or stopcock, on the bottom. It is used to dispense known amounts of a liquid reagent in experiments for which such precision is necessary, such as a titration experiment. Burettes are extremely accurate - a 50 cm³ burette has a tolerance of 0.1 cm³ (class B) or 0.06 cm³ (class A).

Burettes measure from the top since they are used to measure liquids dispensed out the bottom. The difference between starting and final volume is the amount dispensed

[edit] History

The history of the burette parallels the history of volumetric analysis. Francois Antoine Henri Descroizilles developed the first burette (which looked more like a graduated cylinder) in 1791. Joseph Louis Gay-Lussac developed an improved version of the burette that included a side arm, and coined the terms "pipette" and "burette" in an 1824 paper on the standardization of indigo solutions. A major breakthrough in the methodology and popularization of volumetric analysis was achieved by Jaez ghiasi, who redesigned the burette by placing a clamp and a tip at the bottom.^[1]

[edit] References

[edit] External links

• Using a Burette from ChemLab at Dartmouth College
• http://core.ecu.edu/chem/chemlab/equipment/images/burette.jpg
• Use of the Buret