Examination and Improvement of Undergraduate Laboratory Experiment: Thermodynamics of a Surfactant Micellization

Autor/inn/en	Zhang, Qian; Liu, Jie; Nai, Xiao; Bao, Hongcui; Sun, Dezhi; Liu, Min
Titel	Examination and Improvement of Undergraduate Laboratory Experiment: Thermodynamics of a Surfactant Micellization
Quelle	In: Journal of Chemical Education, 97 (2020) 12, S.4490-4498 (9 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Zusatzinformation	ORCID (Zhang, Qian) ORCID (Liu, Jie) ORCID (Liu, Min)
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0021-9584
Schlagwörter	Science Instruction; College Science; Undergraduate Study; Science Laboratories; Laboratory Experiments; Science Experiments; Thermodynamics; Chemistry; Hands on Science; Science Process Skills + Suchen Sie Ihr Suchwort? Teaching of science; Science education; Natural sciences Lessons; Naturwissenschaftlicher Unterricht; Grundstudium; Laboratory work; Laborarbeit; Thermodynamik; Chemie
Abstract	Thermodynamic characterization of micelle formation from an ionic surfactant in aqueous solutions is a classic experiment in physical chemistry. The critical micelle concentration (CMC) and the degree of micelle ionization ([alpha)] can be directly obtained by conductimetry, then thermodynamic parameters ([delta]G[subscript m][superscript o], [delta]H[subscript m][superscript o], [delta]S[subscript m][superscript o]) are deduced from the CMC values at different temperatures. Herein, the CMC values at different temperatures were generated by multiple student groups, and the resulting errors were combined with the enthalpy calculation error for micelle formation ([delta]H[subscript m][superscript o]). Under the presented model it was found that [delta]H[subscript m][superscript o] data were very difficult to obtain using the conductivity method. The isothermal titration microcalorimetry (ITC) method gave a direct [delta]H[subscript m][superscript o] value, which was incorporated into the experiment to determine the accuracy of the surveyed data. The introduction, design, and improvement of a "thermodynamics of 1-tetradecyl-3-methylimidazolium bromide (C[subscript 14]mimBr) micellization" experiment using conductivity and ITC methods were proposed, which may also improve students' experimental ability, practical skills, and quality of research. (As Provided).
Anmerkungen	Division of Chemical Education, Inc. and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2024/1/01