Sciencemadness Discussion Board

Extremely simple melting point apparatus

Haber - 17-4-2014 at 13:39


I thought i might share a very simple mp-apparatus construction that i tested earlier today. Its nothing new I know, but it might still be of intrest for some low budget chemists perhaps:)

This picture pretty much sums it up:

A hole is drilled in a aluminum cpu-fan block (about 1-1.5cm deep), a thermometer is placed in the hole. The sample is placed in the centre of the block. The block is then heated.

Tested the device with benzoid acid, wiki says mp is 122.4C, my "device" gave 123-124C, a slightly higher mp which was expected.

The accuracy is probably not sufficient for alot of applications, but maybe for some (I might also note that i do not know the purity of the compound i tested).

Also my thermometer did not fit perfectly in the hole so i added a drop of oil in the hole to make sure that the probe was heated evenly. The block is also standing in a 2cm deep oil bath, might not be necessary depending on the design of the block.

[Edited on 17-4-2014 by Haber]

Bert - 17-4-2014 at 14:21

Mother of invention- Just don't let your wife see that!

There are several types of heat conductive grease used in "thermowells" of heating and process equipment, another option for the probe hole. Conductive grease for heat sink applications would be good too-