A Guided Inquiry Undergraduate Organic Chemistry Laboratory Experiment - Synthesis and Characterization of an Unknown Solid Ester through Fischer Esterification

A Fischer esterification—an acid-catalyzed reaction between a carboxylic acid and an alcohol—is a popular laboratory exercise in the undergraduate organic chemistry lab. Traditional examples often produce liquid esters, such as banana oil, which can be identified by aroma. In this guided inquiry experiment, students synthesized and characterized solid esters, selected for ease of purification and handling. Students were provided with a list of possible carboxylic acids and alcohols but not the specific reactants assigned to each group. After synthesis, they compared the observed melting point range of their product to a reference table. Furthermore, students recorded the IR, 1 H NMR, and 13 C NMR spectra of their product to confirm their conclusions from the melting point range. This activity required application of critical thinking skills and was widely reported by students as both challenging and enjoyable.