Kipp's apparatus
A Kipp apparatus can be used to produce various gases for use in the laboratory. The gases are created in the required quantity directly from the chemical reaction of a solid with a liquid.
The device was invented by the Delft pharmacist Petrus Jacobus Kipp (1808–1864) in the early 1840s and published in 1844. The device was used in laboratories and for chemical demonstrations in schools well into the second half of the 20th century. It has hardly been used since then, as all common gases are also available in small gas cylinders . These gases are purer and, above all, in contrast to the gases produced in the Kipp apparatus, drier.
Structure and functionality
The Kipp apparatus consists of three glass balloons arranged one above the other. The upper one has an opening at the top, which is often closed with a fermentation tube , and at the bottom a riser pipe that reaches close to the bottom of the lowest glass balloon. The upper balloon is removable and has to be placed gas-tight on the middle balloon, which has a tube with a stopcock on the side for removing the gas and which is fused with the lower balloon.
The middle balloon is separated from the lower one by a sieve or the like so that no solid material can fall into the lower balloon, but gas and liquid can pass over. Solid material is filled in here in pieces or chips .
Then the upper balloon is put on and filled with the appropriate reaction solution with the tap closed. Since the middle balloon forms a closed system, initially only a small amount of liquid flows into the lower balloon and is prevented by the air pressure from rising to the middle balloon.
The development of gas can now be started by opening the tap: The reaction solution now rises into the middle balloon and the chemical reaction begins when it comes into contact with the solid.
If the stopcock is closed, it initially continues to run. However, the resulting gas can no longer escape and therefore leads to an increase in pressure in the apparatus. This pushes the liquid back through the lower balloon and the riser tube into the reservoir at the top. The reaction comes to a standstill as soon as the liquid no longer reaches the solid. If the tap is opened again, the pressure drops, the liquid rises again and covers the solid. The reaction starts again and gas can be withdrawn.
The prerequisite for using the Kipp apparatus is that the solid substance used is not soluble in the liquid used.
Examples of gases that can be generated and their starting materials
- Hydrogen ( zinc shavings and hydrochloric acid )
- Carbon dioxide ( pieces of marble and hydrochloric acid)
- Hydrogen sulfide ( iron (II) sulfide and hydrochloric acid)
- Sulfur dioxide ( sodium hydrogen sulfite and sulfuric acid )
- Ethine ( calcium carbide and water )
- Chlorine (hydrochloric acid and potassium permanganate or manganese dioxide )
- Hydrogen chloride ( ammonium chloride and sulfuric acid)
- Ammonia ( ammonium sulfate or ammonium chloride and concentrated caustic soda )
Web links
- Kipp's apparatus - detailed explanation of the function with pictures and references (English)