The upper chamber extends downward as a tube that passes through the middle chamber into the lower chamber. There is no direct path between the middle and upper chambers, but the middle chamber is separated from the lower chamber by a retention plate, such as a conical piece of glass with small holes, which permits the passage of liquid and gas. The solid material e. The liquid, such as an acid, is poured into the top chamber.
|Published (Last):||1 March 2010|
|PDF File Size:||1.10 Mb|
|ePub File Size:||16.87 Mb|
|Price:||Free* [*Free Regsitration Required]|
Everyone has seen one. Those three bulbs stacked on top of each other with an outlet from the middle section and many of us, no doubt, saw one used in school to generate gases - even if gas cylinders are now favoured in laboratories. It was the last we ever saw of the Kipp which was reduced to smithereens - illustrating once more one of the problems we chemists face: invariably being associated with bangs, stinks and poisoning.
I was immediately hooked. A strong driver for the development of chemistry in the 19th century was the need for quality control and ever more sophisticated methods of analysis to detect fraud, food adulteration and crime. In inorganic analysis, the identification of cations involved the methodical separation of the metals into groups according to their reactions with a set of standard reagents.
In the days before gas cylinders the problem was getting a reliable supply of H2S which you could turn on and off. Analysts across Europe wrestled with the problem and provided elaborate designs for apparatus in the textbooks they wrote. The great German chemist Carl Fresenius , for example, invented a device so complicated it took two pages to describe and which only a madman would use nowadays.
In , a Dutch instrument maker working in Delft, Petrus Jacobus Kipp came up with two designs for simplified apparatus to generate H2S and got the German glassblower Heinrich Geissler of glowing gas tube fame to build them. The rest, as they say, is history. A solid reagent is placed in the middle bulb [C] iron pyrites, if you want to make H2S, or marble chips if you want CO2.
The top bulb [A] is actually a funnel with a long neck that extends down to the bottom of the assembly. Dilute acid is poured in through the top and builds up to react with the solid in the middle bulb, liberating the gas. As gas is produced and the pressure in the lower bulbs increases, the acid is pushed back up the funnel preventing further reaction.
Thus the acid only runs down when gas is drawn off from the valve [D] in the middle bulb. So successful was the device that they are still sold in their hundreds all over the world, a gas generator far cheaper and often easier than small lecture bottles. Just remember not to put a lit taper to the outlet when generating a flammable gas.
Figure 1. Figure 2. It is named after its inventor, the Dutch pharmacist Petrus Johannes Kipp — In any chemical laboratory where analysis is carried out, there needs to be a supply of hydrogen sulfide gas which can be turned on and off at will. Usually when a gas is made in the laboratory, the apparatus has to be set up each time the gas is needed. Furthermore there is no way of switching the supply on and off. The same apparatus can also be used for supplying carbon dioxide or hydrogen on tap.