Micro Hot Stage 1)etrrnminationof melting points of very small quantrtiea is hest done with a micro hot stage. Shown hrre is a hot stage which ran beassembled without aperial~killsormachining and nf low cost. A Cwning P-R:, hot platr, list price 339.50, is the major expense; the other materials total about $10. The body of the hot stage is a 10 g Ohaus slotted weight. This is placed on the hot plate. A Kontes #K-870500-0250thermometer is laced in the slot. The thermometer must be horizontal. The slot is filled with 20 mesh tin bawder, the sample to be melted is placed on the weight, and a 1 x 3 glass slide is placed on the weight so that it covers both the slot and sample. An inexpensive microscope or magnifier is used to observe the sample and the hot plate is set to give a lD/mintemperature rise. Melting points obtained with the above apparatus were identical to those obtained on standard melting point apparatus. Compounds withmelting points between 83°C and 23YC were tested. Beaver College Glenside, Pennsylvania 19038
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Journal of Chemical Education
Dorothy J. Klimis Donald L. Tibbetts
