The question-driven laboratory exercise: A new pedagogy applied to a green modification of grignard reagent formation and reaction

Experimental exercises within second-year-level organic laboratory manuals typically involve a statement of a principle that is then validated by student generation of data in a single experiment. These experiments are structured in the exact opposite order of the scientific method, in which data interpretation, typically from multiple related experiments, leads to the development of a principle. The question-driven laboratory exercise (QDLE) better mimics a research investigative process in that data from multiple experiments provided to students are coupled with student-generated data with the goal being the development of a principle. To facilitate students' ability to tether together interpretations from multiple experiments, the entire exercise is driven by guiding questions. This general approach is applicable to a broad array of potential laboratory exercises. In this example, students are guided to develop a more environmentally friendly solvent system for Grignard formation and reaction, test the new system via a laboratory experiment, and then discern between two competing proposed mechanisms for describing Grignard reagent formation in the modified media. To accomplish this goal, the students will be guided to interpret and synthesize data (some provided, some student generated) from ¹³C NMR, GC-MS, and computational investigations.