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
Also used for buretting are buretting syringes. These are calibrated to Volumetric A grade tolerances which are equal to or better than the traditional burette tolerance. The graduated buretting tube is provided with a thumb operated piston and PTFE seal which slide within the tube in a positive displacement operation. This arrangement is provided to achieve improvements in reliability, by removing problems of bubble entrapment while filling, leaks and blockages in stopcock mechanisms. The design also addresses handling safety, economy, and versatility when handling volumes between 0.5 and 25mL. The buretting syringe is set up in a traditional burette holder or used freehand. The positive displacement action enables it to handle any laboratory fluid – viscous and volatile, hydrocarbons, essential oils and mixtures, with great accuracy. Other features of the buretting syringe are the provision of a red line on the sliding seal which may be read instead of the meniscus, thus virtually eliminating parallax error, and its robust form which makes it more resistant to breakage and easier to clean. Developed by Blackwood-eddy pty. ltd., Australia, the buretting syringe’s simplicity and effectiveness have led to its wide adoption by Australasian high schools and university chemistry departments, and for a wide variety of industrial applications.
Beaker · Büchner funnel · Burette · Cold finger · Condenser · Conical measure · Cuvette · Dropping funnel · Eudiometer · Gas syringe · Graduated cylinder · Pipette · Petri dish · Pycnometer · Separatory funnel · Soxhlet extractor · Watch glass
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