Round bottom flask

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Different single-necked round bottom flasks in side view.
Two- and three-necked round bottom flasks (the latter in two variants) in the side view.
Round bottom flasks with standard ground joint, different sizes

Round-bottom flasks consist of a lower spherical part and a cylindrical neck. They are made of Duran (glass) (formerly Jenaer Glas ) and standardized according to DIN / ISO reaction vessels in chemistry . They are made in various sizes (from 10 ml to 25 l) and also as multi-neck flasks with straight or side necks. Round-bottom flasks made of amber glass are also occasionally used in the laboratory.

Further versions :

  • Narrow neck and wide neck flasks
  • Long neck and short neck flasks
  • Pistons with or without "ground joint " ( standard ground joint , spherical ground joint or similar).

Round bottom flasks with standard ground joint have many different sleeve sizes in the laboratory. The most common, NS 29/32, is used to connect additional glass devices (e.g. coolers). In addition, round-bottom flasks with a spherical joint are used in laboratories and technology , e.g. B. as a collecting vessel for the distillate on rotary evaporators .

In contrast to flat-bottom flasks (e.g. Erlenmeyer flasks ), round-bottom flasks may be placed under vacuum without the risk of implosion . In addition, the round shape enables even heating.

See also

literature

  • DIN ISO 1773: 1999-05 Laboratory glassware - Erlenmeyer, round and flat bottom flasks, narrow neck (ISO 1773: 1997) , May 1999.
  • DIN EN ISO 24450: 2006-02 Laboratory glassware - Erlenmeyer, round and flat-bottom flasks, wide neck (ISO 24450: 2005); German version EN ISO 24450: 2005 , February 2006.
  • DIN EN ISO 4797: 2005-03 Laboratory glassware - Erlenmeyer, round and flat bottom flasks with conical ground joint (ISO 4797: 2004); German version EN ISO 4797: 2004 , March 2005.

Individual evidence

  1. ^ Walter Wittenberger: Chemische Laboratoriumstechnik , Springer-Verlag, Vienna, New York, 7th edition, 1973, pp. 18-19, ISBN 3-211-81116-8 .