Burettes

Burette

A burette is a laboratory equipment used in analytical chemistry for the dispensing of variable, measured amounts of a chemical solution. It is a long, graduated glass tube with a stopcock at its lower end for controlling the liquid flow. Burettes are most commonly used in titration, a process where a measured volume of a solution of known concentration is used to determine the concentration of an unknown solution.

History

The development of the burette has its roots in the late 18th century, with improvements and refinements continuing through the 19th century. The precise control of liquid flow it offered was a significant advancement in the field of quantitative analysis.

Design and Function

A typical burette has a cylindrical shape with a graduation scale along its length, measured in milliliters. The stopcock, or valve, can be glass or Teflon, and it allows for the precise control of liquid flow. The accuracy of a burette makes it an essential tool in laboratories for performing titrations and other quantitative analytical procedures.

Types of Burettes

There are two main types of burettes used in laboratories:

• Glass burettes, which are suitable for most aqueous solutions but can be corroded by strong acids or bases.
• Teflon-coated burettes, which are resistant to corrosive chemicals and are preferred for use with strong acids and bases.

Usage

The primary use of a burette is in the process of titration, which involves the gradual addition of a titrant solution from the burette to a known volume of a sample (analyte) until the reaction reaches its endpoint. This process is used to determine the concentration of the analyte. Burettes are also used in other laboratory procedures that require precise measurements of liquid volumes.

Maintenance and Calibration

Proper maintenance and calibration are essential for the accurate operation of burettes. They must be cleaned regularly and checked for any damage or irregularities. Calibration involves checking the volume markings on the burette against a standard volume to ensure accuracy.

Safety Considerations

When using a burette, it is important to follow safety protocols to prevent accidents, such as wearing protective eyewear and gloves, especially when handling corrosive chemicals.

See Also

• Titration
• Laboratory equipment
• Analytical chemistry

Burettes Resources
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