The Siwoloboff method is used to determine the boiling point of small samples of liquid chemicals. A sample in an
ignition tube
A test tube, also known as a culture tube or sample tube, is a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top and closed at the bottom.
Test tubes are usually placed in ...
(also called a fusion tube) is attached to a thermometer with a rubber band, and immersed in a
Thiele tube
The Thiele tube, named after the German chemist Johannes Thiele, is a laboratory glassware designed to contain and heat an oil bath. Such a setup is commonly used in the determination of the melting point of a substance. The apparatus resembles ...
, water bath, or other suitable medium for heating. A sealed capillary, open end pointing down, is placed in the ignition tube.
The apparatus is heated. Dissolved gases evolve from the sample first, and the air in the capillary tube expands. Once the sample starts to boil, heating is stopped, and the temperature starts to fall. The temperature at which the liquid sample is sucked into the sealed capillary is the boiling point of the sample.
References
Laboratory techniques
{{Analytical chemistry