Flask (vessel)

Different glass flasks

Marie Curie glass flask.

In chemistry or common in laboratories bulbous vessels (usually glass containers ) and piston (from Middle High German kolbe , "pistons, Flask" as piston-shaped glass tableware also called piston-glass ), respectively. Size, shape and material (for example: glass , borosilicate glass , PE , Teflon) vary depending on the intended use. Flasks, which are used for distilling or heating liquids , are usually made of heat-resistant borosilicate glass.

The figure shows from left to right two volumetric flasks of different sizes (flat bottom, adjusted to certain volumes, are used, for example, to prepare standard solutions), an Erlenmeyer flask (flat bottom and wide neck, for example for titration ), a three- necked flask (reaction vessel ) and a rotary evaporator flask (for evaporation of liquids at elevated temperature and vacuum ). There are also many other embodiments of Flask: flat-bottomed flask (similar to a round bottom flask, but with a flat bottom), pear or Walter flask Kjeldahl flask (use in the analysis of nitrogen according to Kjeldahl ) (, two-necked flask and three-neck flask used in the Synthesis ) and pointed flasks (for use as receptacles under a spider). Most of these flasks have a standard ground joint so that they can be easily installed in complicated glass equipment.

In electrical engineering , a flask creates the separation between the gas mixtures of the earth's atmosphere that people are used to and a special environment inside the flask ( vacuum , air, vapor or gas filling with noble gases at low pressure , e.g. mercury vapor ) created for the respective purpose . Mostly these consist of glass or ceramic , less often of metal ( steel ). The materials must be sufficiently gas-tight and withstand mechanical loads (pressure difference!). Electrical connections are made using fused or insulated lead-through wires. Example: pinch foot . The term bulb is shown very clearly in incandescent lamps , older electron tubes, cathode ray tubes and mercury vapor rectifiers due to their often bulbous shape.

See also

• Round bottom flask
• Sulphurizing flask

Web links

Commons : Pistons  - collection of images, videos and audio files

Wiktionary: piston  - explanations of meanings, word origins, synonyms, translations

Wikiquote: Pistons  - Quotes

Individual evidence

1. ^ Rudolf Schmitz : Mortars, flasks and vials. From the world of pharmacy. Stuttgart 1966; Reprint (extended by a foreword) Graz 1978.
2. ↑ Jürgen Martin: The 'Ulmer Wundarznei'. Introduction - Text - Glossary on a monument to German specialist prose from the 15th century. Königshausen & Neumann, Würzburg 1991 (= Würzburg medical-historical research. Volume 52), ISBN 3-88479-801-4 (also medical dissertation Würzburg 1990), p. 143.
3. ^ Brockhaus ABC chemistry. Volume 2: L - Z. VEB FA Brockhaus Verlag, Leipzig 1965, pp. 702-703.
4. ^ Walter Wittenberger: Chemical laboratory technology. An aid book for laboratory technicians and technical students. 7th, completely revised edition. Springer, Vienna et al. 1973, ISBN 3-211-81116-8 , pp. 18-19.