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An Erlenmeyer flask or conical flask is a type of laboratory flask which features a flat bottom, a conical body, and a cylindrical neck. It is named after the German chemist Emil Erlenmeyer, who created it in 1860.
Erlenmeyer flask have wide bases, with sides that taper upward to a short vertical neck. They may be graduated, and there are often spots of ground glass or enamel where they can be labeled with a pencil. It differs from the beaker in its tapered body and narrow neck.
The mouth of the Erlenmeyer flask can have a beaded lip that can be stoppered using a piece of cotton wool, rubber bung or similar. Alternatively, the neck may be fitted with a female ground glass joint to accept a glass stopper.
The tapered sides and narrow neck of this flask allow the contents of the flask to be mixed by swirling, without risk of spillage, making them suitable for titrations. Such features similarly make the flask suitable for boiling liquids. Hot vapors condense on the upper section of the Erlenmeyer flask, reducing solvent loss. Erlenmeyer flasks' narrow necks can also support filter funnels.
The last two attributes of Erlenmeyer flasks make them especially appropriate for recrystallization. The sample to be purified is heated to a boil, and sufficient solvent is added for complete dissolution. The receiving flask is filled with a small amount of solvent, and heated to a boil. The hot solution is filtered through a fluted filter paper into the receiving flask. Hot vapors from the boiling solvent keep the filter funnel warm, avoiding premature crystallization.
Erlenmeyer flasks are also used 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.
- Andrea Sella (July 2008). "Classic Kit: Erlenmeyer flask". Royal Society of Chemistry.
- Emil Erlenmeyer, "Zur chemischen und pharmazeutischen Technik," Zeitschrift fuer Chemie und Pharmacie, vol. 3 (January 1860), 21-22. He wrote that he first displayed the new flask at a pharmaceutical conference in Heidelberg in 1857, and that he had arranged for its commercial production and sale by local glassware manufacturers.
- Laboratory Glassware. 17 November 2011
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