- Thiele tube
The Thiele tube, named after the German chemist Johannes Thiele, is a
laboratory glassware designed to contain andheat anoil bath . Such a setup is commonly used in the determination of themelting point of asubstance . The apparatus itself resembles a glasstest tube with an attached handle.Operation
Oil is poured into the tube, and a then the "handle" is heated, either by a small flame or some other heating element. The particular shape of the Thiele tube allows the oil to circulate via a convection current, thus producing an oil bath of nearly uniform temperature.
Melting point determination
A sample in a sealed capillary, attached to a
thermometer with a rubber band, is immersed in the tube. Heating is commenced, and the temperature ranges at which the sample melts can be then be observed. [cite web | publisher =University of Calgary | title = Melting Point Determination | url = http://www.chem.ucalgary.ca/courses/351/laboratory/meltingpoint.pdf] A more modern method utilizes dedicated equipment, known as amelting point apparatus .Boiling point determination
A sample in a
fusion tube is attached to a thermometer with a rubber band, and immersed in the tube. A sealed capillary, open end pointing down, is placed in the fusion tube. The Thiele tube is heated; dissolved gases evolve from the sample first. 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. [cite web | publisher =University of Calgary | title = Boiling Point Determination | url = http://www.chem.ucalgary.ca/courses/351/laboratory/boilingpoint.pdf]References
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