Erlenmeyer flask

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An Erlenmeyer flask is a widely used type of laboratory flask which features a conical base with a cylindrical neck. They are usually marked on the side (graduated) to indicate the approximate volume of their contents. It is named after the German chemist Emil Erlenmeyer, who created it in 1861.

The conical flask is similar to the beaker, but is distinguished by its narrow neck. The neck allows the flask to be stoppered using rubber bungs or cotton wool. The conical shape allows the contents to be swirled or stirred during an experiment (as is required in titration); the narrow neck keeps the contents from spilling. The smaller neck also slows evaporative loss better than a beaker. The flat bottom of the conical flask makes it unlikely to tip over, unlike the Florence flask.

Erlenmeyer flasks are used for pH titrations and in microbiology for the preparation of microbial cultures. Plastic erlenmeyer flasks used in cell culture are pre-sterilized and feature closures and vented closures to enhance gas exchange during incubation and shaking.

If the flask is to be heated in an oil or water bath, a 'C' shaped lead or iron weight may be placed over the outside to keep the flask firmly planted.

When heating, it is usually placed on a ring held to a ring stand by means of a ring clamp. The ring keeps it over a Bunsen burner so that it is heated by the flame of the burner. When set up this way, a wire gauze mesh or pad is placed between the ring and the flask to prevent the flames from directly touching the glass. An alternative way to set up the apparatus is to clamp the flask directly to the ring stand by means of holding it with a test tube clamp around the neck of the flask.

See also

• Fleaker

References