Woulfesche bottle

Woulfesche bottle, Duran glass

The Woulfe bottle [ ˈwʊlf- ] (after Peter Woulfe , who published the first description in 1767), also called Woulfe bottle, Woulff bottle, Woulffe bottle, Woulff bottle, Woulf bottle or Woulfe apparatus , is a laboratory device , which is now used almost exclusively in vacuum devices.

Today, Woulfe bottles are mostly made of glass, have a cylindrical shape and, thanks to their thick walls, are stable under negative pressure . In the past they had two, now usually three necks (tubes) on the top, which are now provided with screw threads or designed as a ground joint .

use

Woulfe bottles have been used in many different ways over the centuries.

Production of gas solutions

Initially, Woulfe bottles were mainly used to collect or dissolve gases in liquids. For this purpose, Woulfe bottles were also made from earthenware and then mainly used in the production of hydrochloric acid . Here, the mostly freshly produced gas is introduced into the liquid (the solvent) through a glass tube, which is led through one of the necks of the Woulfe bottle and extends to the bottom. Undissolved gas can be discharged through another neck. All openings could then be closed with stoppers and the gas solution stored in this way.

Gas development vessel

Use of the Woulfe bottle for gas generation (historical illustration)

Woulfe bottles can also be used to produce a gas, which is then transferred to a second container and stored there. For example, hydrogen can be generated by placing granulated zinc in the Woulfe bottle, covering it with water and adding diluted sulfuric acid through a thistle funnel :

{\ displaystyle \ mathrm {Zn + H_ {2} SO_ {4} \ longrightarrow ZnSO_ {4} + H_ {2} (g)}}

Reaction of zinc in dilute sulfuric acid to release hydrogen

The hydrogen that develops is transferred through a glass tube into a second vessel, where it is collected, for example by displacing a sealing liquid such as water.

Gas washing bottle

Several Woulfe bottles arranged in series for cleaning and / or drying gases

A series connection of Woulfe bottles can be used to wash out the secondary components of a contaminated or moist gas and to dry it. For this purpose, appropriate washing liquids are filled into the Woulfe bottles, in which the impurities are readily soluble, but the gas to be purified is poorly soluble. Baryta water is used here, for example, to remove carbon dioxide , concentrated sulfuric acid for drying, hydrochloric acid to trap basic components such as ammonia or amines and sodium hydroxide solution to neutralize acidic gases such as sulfur dioxide .

Vacuum intermediate vessel

Today, Woulfe bottles are usually used as part of a vacuum apparatus. To do this, they must be able to withstand external overpressure. Often the bottles made of glass are also coated with a tough plastic film, which helps to prevent splinters in the event of bursting.

In this experimental setup, the Woulfe bottle (left, with manometer) is connected to a membrane pump in order to generate a negative pressure in the reaction apparatus in the center of the picture.

The apparatuses are set up in such a way that the vacuum pump is connected to a tube of the Woulfe bottle , another tube is used to connect the vessel to be evacuated or the apparatus to be evacuated. A tap for vacuum regulation or a pressure measuring device or a combination of both can be installed in the third to regulate and control the pressure.

If a water jet pump is used to generate a vacuum , a sudden drop in water pressure by a Woulf's bottle prevents the remaining water still present in the pump from being sucked into the evacuated reaction apparatus and either causing a chemical reaction to fail there dangerous reactions occur. The remaining water is collected in the Woulff bottle placed in between. Conversely, liquids from the reaction apparatus are also caught by the Woulf bottle and never get into the pump.

At the same time, the Woulfe bottle serves as a vacuum reservoir.

literature

DIN 12480: 2009-12 Laboratory glassware - three-neck bottles - Woulff bottles , December 2009.

Individual evidence

↑ Peter Woulfe: Experiments on the Distillation of Acids, Volatile Alkalies, & c. Shewing How They May be Condensed without Loss, and How Thereby We May Avoid Disagreeable and Noxious Fumes , Philosophical Transactions 1767, p. 517.
^ Meyers Konversations-Lexikon, 1885: Woulfesche bottle .
^ RP Rana: Chemistry For Middle Class-8 (Book-III) , ISBN 81-219-2689-0 , p. 3.
↑ S. Ebel and HJ Roth (editors): Lexikon der Pharmazie , Georg Thieme Verlag, 1987, p. 691, ISBN 3-13-672201-9 .
^ Walter Wittenberger: Chemische Laboratoriumstechnik , Springer-Verlag, Vienna, New York, 7th edition, 1973, p. 259, ISBN 3-211-81116-8 .

Web links

Commons : Woulfesche bottles - collection of images, videos and audio files

Illustration of historical Woulfescher bottles in the Museum of the Jagiellonian University in Krakow

[1] Peter Woulfe: Experiments on the Distillation of Acids, Volatile Alkalies, & c. Shewing How They May be Condensed without Loss, and How Thereby We May Avoid Disagreeable and Noxious Fumes , Philosophical Transactions 1767, p. 517.

[2] Meyers Konversations-Lexikon, 1885: Woulfesche bottle .

[R.P._Rana-3] RP Rana: Chemistry For Middle Class-8 (Book-III) , ISBN 81-219-2689-0 , p. 3.

[Ebel-4] S. Ebel and HJ Roth (editors): Lexikon der Pharmazie , Georg Thieme Verlag, 1987, p. 691, ISBN 3-13-672201-9 .

[Wittenberger-5] Walter Wittenberger: Chemische Laboratoriumstechnik , Springer-Verlag, Vienna, New York, 7th edition, 1973, p. 259, ISBN 3-211-81116-8 .