Didactic Approach on Chemical and Dynamic Equilibrium with the Laboratory Investigation of Oppenauer Oxidation (OPP) and Meerwein–Ponndorf–Verley Reduction (MPV) Reactions

Abstract

Connecting the textbook definition and mechanisms of oxidation and reduction with practical applications is a lasting challenge for early undergraduate students. This Laboratory Experiment presents the design and implementation of a cost-effective pedagogical experiment of complementary redox reactions (MPV reduction and OPP oxidation) to strengthen first-year undergraduate students’ understanding of the principle of oxidation and reduction with an emphasis on the identification of oxidizing agents, reducing agents and equilibrium through a hands-on lab experiment. This module deals with Meerwein–Ponndorf–Verley (MPV) reduction of acetophenone to 1-phenylethanol using isopropyl alcohol and Oppenauer (OPP) oxidation reactions of 1-phenylethanol back to acetophenone using acetone. This experiment bridges the understanding of students with the laboratory observations monitored by thin-layer chromatography (TLC) with 1H NMR spectroscopy for characterization of products and the Lucas test for confirmation of secondary alcohol formation. Students’ assessment through lab reports achieved 60–93% yields in both (MPV and OPP) reactions. Moreover, the mean score difference for the prelab test (mean = 3.68) and postlab questions (mean = 7.24) supplemented by suitable open-ended structured probing questions was found to be significant at the 0.05 level (p < 0.05), showing a marked improvement in conceptual understanding. This module, which can be replicated in any educational setup with the use of the provided supporting material, has successfully strengthened the core redox terminologies, equilibrium concepts, and practical skills in students.