ERIC Number: EJ1043261
Record Type: Journal
Publication Date: 2014-Oct
Abstractor: As Provided
Reference Count: 12
Pedagogical Comparison of Five Reactions Performed under Microwave Heating in Multi-Mode versus Mono-Mode Ovens: Diels-Alder Cycloaddition, Wittig Salt Formation, E2 Dehydrohalogenation to Form an Alkyne, Williamson Ether Synthesis, and Fischer Esterification
Baar, Marsha R.; Gammerdinger, William; Leap, Jennifer; Morales, Erin; Shikora, Jonathan; Weber, Michael H.
Journal of Chemical Education, v91 n10 p1720-1724 Oct 2014
Five reactions were rate-accelerated relative to the standard reflux workup in both multi-mode and mono-mode microwave ovens, and the results were compared to determine whether the sequential processing of a mono-mode unit could provide for better lab logistics and pedagogy. Conditions were optimized so that yields matched in both types of microwave ovens for a Diels-Alder cycloaddition, Wittig salt formation, Fischer esterifications, an E2 alkyne formation, and Williamson ether synthesis. Typically, a 10-fold rate acceleration was observed under mono-mode heating versus multi-mode heating, reducing the total run-time between 1.5 and 3.0 min per sample, which rivals the batch run-time of a multi-mode unit in ~16 student lab sections. Thus, the mono-mode microwave oven required a similar quantity of total reaction time in the lab, allowing students to run their experiments individually with less wait-time, competition for chemicals, equipment, and instrumentation and to complete the experiments in the lab period.
Descriptors: Science Instruction, Science Experiments, Laboratory Equipment, Undergraduate Study, College Science, Hands on Science, Scientific Concepts, Chemistry, Energy, Heat, Teaching Methods
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: firstname.lastname@example.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education; Postsecondary Education
Authoring Institution: N/A