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The Chemical Educator
ISSN: 1430-4171 (electronic version)
Abstract Volume 18
(2013) pp 203-208
DOI 10.1007/s00897132500
True Melting Point Determination
John C. O’C. Young
Department of Chemistry, Saint Mary’s University, Halifax, Nova Scotia, Canada, B3H 3C3, john.young@smu.ca
Received May 17, 2013. Accepted June 21, 2013.
Published: 19 July 2013
Abstract. While pure compounds melt isothermally at constant pressure, their melting points are commonly reported as the range between the temperatures recorded by a heated capillary-type melting range measuring instrument at the onset and at the completion of melting of a sample as determined by a pharmacopeiac test protocol. Based on the use of a simple, low-cost version of this type of instrument, a procedure is presented and exemplified for determining the true “thermodynamic” melting points of pure compounds from such melting range data.
Key Words: Laboratories and Demonstrations; physical chemistry; laboratory instrumentation
(*) Corresponding author. (E-mail: john.young@smu.ca)
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