Determining the Energy of Activation of a Salt, Water, and Alcohol Emulsion

Autor/inn/en	Nydegger, Michael; Bartlett, Ashlee; Leverentz-Culp, Hannah R.
Titel	Determining the Energy of Activation of a Salt, Water, and Alcohol Emulsion
Quelle	In: Journal of Chemical Education, 97 (2020) 10, S.3746-3750 (5 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Zusatzinformation	ORCID (Leverentz-Culp, Hannah R.)
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0021-9584
Schlagwörter	Science Experiments; Energy; College Freshmen; Science Instruction + Suchen Sie Ihr Suchwort? Energie; Studienanfänger; Teaching of science; Science education; Natural sciences Lessons; Naturwissenschaftlicher Unterricht
Abstract	A highly visual, inexpensive, straightforward laboratory experiment for the determination of the activation energy of a demulsification process is presented. The experiment uses low-density polyethylene (LDPE) beads to clearly mark the interface between an NaCl(aq) solution and isopropanol. The NaCl(aq)-isopropanol system is shaken to produce an emulsion, and the rate of demulsification is subsequently observed at different temperatures. The Arrhenius equation is then used to relate the rate and temperature data to an energy of activation for the demulsification process. A total of 36 undergraduate laboratory groups in first-year chemistry courses performed this experiment. The students' data consistently yielded linear Arrhenius plots with an average R2 value of 0.928 ± 0.035. The activation energy of the demulsification process described in this work was found to be 34.3 ± 2.5 kJ/mol. The reproducibility of the results, the simplicity of the data collection, and the low cost of the materials make this laboratory exercise easily adaptable to a variety of grade levels, from middle school students to first-year college students. (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