Burette

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A burette is a lab device used in analytical chemistry for the dispensing of variable, measured amounts of a chemical solution.

General

Burettes come in two main categories:

  • Volumetric burette: delivers measured volumes of liquid.
  • Weight burette: delivers measured weights of liquid.

Types

Automatic burette

Consist of a specially designed burette, fitted with a flat bottom flask, which contains the solution. Filling the burette is done by pumping air inside the burette flask by squeezing a small bulb pump and covering the lower air vent with your finger.

Electronic

Uses a small computer to measure and release exact amounts of solution. They are generally screwed on a large bottle, which is filled with the desired liquid/solution.

Straight burette

Consists of a long glass tube, with a glass or PTFE stopcock at one end. Filling the burette is done manually, from the top, or in case of thin burettes, using a rubber bulb to draw liquid from the end, in a similar way to pipettes.

Maintenance

Burettes should be cleaned often to prevent the capillaries from clogging up.

For safety reasons, burettes should always be kept filled with a liquid when not in use or covered. This is not required for automatic burettes.

See also

References

Relevant Sciencemadness threads