STEVE HORRELL / SCIENCE PHOTO LIBRARY STEVE HORRELL / SCIENCE PHOTO LIBRARY
Burette. Valve and tip of a laboratory burette with the tip placed inside the neck of a flask. In the background is a measuring cylinder (at left) and a volumetric flask (at right). A burette is a graduated glass tube from which a variable, accurate quantity of fluid can be delivered by means of manually opening and closing the valve (at upper centre). Burettes are used in a wide variety of applications in analytical chemistry, particularly in volumetric analysis or titration. Titrations are determinations of the concentration of one fluid, such as an acid, by slowly adding a solution of known concentration which neutralises it, such as an alkali.
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