NotesFAQContact Us
Collection
Advanced
Search Tips
Back to results
Peer reviewed Peer reviewed
Direct linkDirect link
ERIC Number: EJ1154148
Record Type: Journal
Publication Date: 2017-Sep
Pages: 5
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0021-9584
Cross-Course Collaboration in the Undergraduate Chemistry Curriculum: Primary Kinetic Isotope Effect in the Hypochlorite Oxidation of 1-Phenylethanol in the Physical Chemistry Laboratory
Noll, Robert J.; Fitch, Richard W.; Kjonaas, Richard A.; Wyatt, Richard A.
Journal of Chemical Education, v94 v9 p1338-1342 Sep 2017
A kinetic isotope effect (KIE) experiment is described for the physical chemistry laboratory. Students conduct a hypochlorite (household bleach) oxidation of an equimolar mixture of 1-phenylethanol and 1-deuterio-1-phenylethanol to acetophenone. The reaction occurs in a biphasic reaction mixture and follows first-order kinetics with respect to either isotopomer of 1-phenylethanol. Reaction progress is measured by gas chromatography-mass spectrometry (GC-MS). Alternatively, the experiment could be conducted with each isotopomer serially and followed by GC alone. The reaction rate constant for the disappearance of 1-phenylethanol, k[subscript H], ranges from 3 × 10[superscript -4]to 2 × 10[superscript -3] s[superscript -1] , while k[subscript D,] for 1- deuterio-1-phenylethanol, ranges from 9 × 10[superscript -5] to 5 × 10[superscript -4] s[superscript -1] . The observed KIE, the ratio k[subscript H]/k[subscript D]is remarkably robust, ranging between 2.3 and 3.6, with a mean of 2.9 and standard deviation of 0.4 over three years of student data. The robustness of the observed KIE stems from using competing reactions. The experiment can be completed in about 3 h; GC-MS data is conveniently acquired overnight using an autosampler. The experiment, as presented here, can stand alone, but is well-suited to cross-course collaboration between the organic and physical chemistry laboratories. The preceding companion paper describes the synthesis of 1-phenylethanol and 1-deuterio-1- phenylethanol using borohydride or borodeuteride reduction of acetophenone as an experiment for the organic laboratory.
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
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: National Science Foundation (NSF)
Authoring Institution: N/A
Grant or Contract Numbers: DUE0942345