Identifying Unknown Analgesics

We designed a new introductory experiment for organic chemistry laboratory using the four most common over-the-counter (OTC) oral analgesics. This experiment allows students to make connections to several fundamental concepts they learn in organic chemistry: from the prevalence of organic compounds in medicine, what defines organic acid, how to predict acid-base reactions from pKa values, and the solubility rule, to the common functional groups of an organic compound and their polarity. Students will also get their first exposure to basic techniques in organic chemistry laboratories such as extraction, thin layer chromatography, column chromatography, filtration, rotary evaporation (vacuum distillation), and melting point determination.