Interactive Demonstrations for Mole Ratios and Limiting Reagents
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Crystal Wood [1] ; Bryan Breyfogle [1]
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[1] Missouri State University
Missouri State University
Township of Springfield, Estados Unidos
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 83, Nº 5, 2006, pág. 741
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
The objective of this study was to develop interactive lecture demonstrations (ILD) based on conceptual-change learning theory. Experimental instruction was designed for an introductory chemistry course for nonmajors to address misconceptions related to mole ratios and limiting reagents. Students were asked a series of questions related to two chemical demonstrations via an electronic keypad system. Questions asked during the demonstrations included conceptual items, particulate items, and traditional textbook-style calculations. Results indicate that use of the ILDs decreased students' misconceptions and that they were a positive addition to the course. Students' understanding was determined via a pretest and posttest that included multiple-choice and free-response questions. Students showed significant improvement on the multiple-choice items after instruction. Evaluation of free-response items via a rubric indicated that participants understanding of stoichiometry increased. A large majority of student evaluations suggested that the interactive system had a positive effect on their learning.
