Schlenk flask

Schlenk flask

A selection of Schlenk flasks and, bottom right, a Schlenk tube
Other names	Schlenk tube
Uses	Vacuum Inert gas
Inventor	Wilhelm Schlenk
Related items	Schlenk line

A Schlenk flask, or Schlenk tube, is a reaction vessel typically used in air-sensitive chemistry, invented by Wilhelm Schlenk. It has a side arm fitted with a PTFE or ground glass stopcock, which allows the vessel to be evacuated or filled with gases (usually inert gases like nitrogen or argon). These flasks are often connected to Schlenk lines, which allow both operations to be done easily.

Schlenk flasks and Schlenk tubes, like most laboratory glassware, are made from borosilicate glass such as Pyrex.

Schlenk flasks are round-bottomed, while Schlenk tubes are elongated. They may be purchased off-the-shelf from laboratory suppliers or made from round-bottom flasks or glass tubing by a skilled glassblower.