Acid-base chemistry, an essential component of the undergraduate chemistry curriculum, is introduced in general chemistry and expanded on in organic chemistry. Previous research has linked student understanding of acid-base chemistry to success in organic chemistry. However, there remains a paucity of information regarding how students apply acid-base chemistry concepts in the context of organic reaction mechanisms. The purpose of this study was to analyze the resources activated in second-semester organic chemistry students understanding while solving problems on E1, E2, and E1cB elimination reactions. The resources activated were probed using a mixed-methods approach comprising survey assessments and think-aloud interviews, and the data were analyzed both quantitatively and qualitatively following a validated set of scoring criteria. The results align with existing findings that students focus upon surface level structural information and use more familiar resources when solving organic problems. Acid-base resources were activated more often than reaction-specific resources such as conformational analyses or carbocation rearrangements. Acid-base resources aid students in successfully analyzing reaction mechanisms, but in general, additional resources must be activated to rationalize specific mechanisms and explain the products formed. The implications for teaching, assessment, and future research are discussed.

Acid-base chemistry is an essential component of the undergraduate chemistry curriculum, introduced in general chemistry and expanded on in organic chemistry. Previous research has linked student understanding of acid-base chemistry to success in organic chemistry. However, there remains a paucity of information regarding how students apply acid-base chemistry concepts in the context of organic reaction mechanisms. The purpose of this study was to describe second-semester organic chemistry students’ understanding of acid-base chemistry principles in the E2, E1, and E1cB elimination reactions. Student understanding was probed using a mixed-methods approach comprising survey assessments and think-aloud interviews, and the data were analyzed both quantitatively and qualitatively following a validated set of scoring criteria. In general, the results from this study support existing findings that acid-base recognition and identification of surface-level structural features are the concepts that are first constructed by students. However, this study also suggests that the construction of these concepts may function as a double-edged sword; acid-base chemistry can be used to explain reaction mechanisms, but it may also hinder the development of a deeper understanding of organic reactivity. Implications for teaching and future research are discussed.