Browsing by Author "Oliver-Hoyo, Maria T."
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Item An esterification kinetics experiment that relies on the sense of smell(Division of Chemical Education of the American Chemical Society, 2009-01) Bromfield-Lee, Deborah C.; Oliver-Hoyo, Maria T.This experiment involves an esterification synthesis to study reaction kinetics where students explore these topics utilizing the sense of smell rather than the traditional approach of using spectroscopic methods. Students study the effects of various factors including the concentration of the carboxylic acid and the amounts of the catalyst or alcohols added. The kinetics in relation to the molecular structure is studied by changing the chain lengths and branching of alcohols or the carboxylic acids and inferring the effects on rates of the reaction from the rates of ester detection. Since many esters have naturally occurring aromas that are pleasant and easily recognized, this experiment studies esterification kinetics using the sense of smell to detect the emergence of the ester aroma formed during the reaction. Feedback from students strongly suggests their interest in the experiment as they discovered that their sense of smell could be used as an analytical tool.Item A qualitative organic analysis that exploits the senses of smell, touch, and sound(Division of Chemical Education of the American Chemical Society, 2007-12) Bromfield-Lee, Deborah C.; Oliver-Hoyo, Maria T.This laboratory experiment utilizes the characteristic aromas of some functional groups to exploit the sense of smell as a discriminating tool in an organic qualitative analysis scheme. Students differentiate a variety of compounds by their aromas and based on their olfactory classification identify an unknown functional group. Students then perform chemical tests that rely on the senses of touch, smell, and sound to confirm the functional group present. The use of a light probe enables students to qualitatively analyze many visual changes as an auditory response. Students "hear" significant changes in color, solution viscosity, and the presence of a precipitate. Students group compounds by their functional group characteristic smells, decide on necessary confirmatory tests based on their own classification, and utilize effectively the senses of touch, sound, and smell to identify their unknowns. Student feedback strongly stated they enjoyed the experiment particularly discovering the characteristics of each functional group physically and chemically. Based on the write-ups and performance of the students in the laboratory, it is evident that this sensorial laboratory can add richness to traditional organic laboratories.Item Using laboratory chemicals to imitate illicit drugs in a forensic chemistry activity(Division of Chemical Education of the American Chemical Society, 2008-06) Hasan, Shawn; Bromfield-Lee, Deborah C.; Oliver-Hoyo, Maria T.; Cintron-Moldonado, Jose A.This forensic chemistry activity utilizes presumptive forensic testing procedures and laboratory chemicals that produce screening results similar to controlled substances. For obvious reasons, obtaining heavily regulated controlled substances to create an undergraduate student activity is not practical for most educational institutions. We were able to identify over-the-counter and laboratory chemicals that mimic actual street drugs in terms of physical properties and color response. Using these selected chemicals, the screening aspect of drug testing provides students with the opportunity to understand what obstacles a forensic chemist faces when analyzing a sample of unknown identity. Chemical spot tests (CSTs) and thin-layer chromatography (TLC) were chosen owing to their simplicity, versatility, common use by forensic chemists, availability, and cost of the reagents and equipment needed. Students are expected to explain how simple color reactions can screen for illicit drugs, to describe how TLC can be used to separate and tentatively identify drugs, to predict how polarity changes affect TLC results, and to explain why CSTs and TLC serve for screening purposes only.