This study investigated the possible connection between effective laboratory activities and student performance on lecture exams. In a traditional undergraduate organic chemistry course for non-science majors, students could predict the products of organic reactions, but struggled to provide reaction mechanisms for those same reactions, despite obtaining perfect scores on their laboratory reports where reaction mechanisms were required. In addition, student attitudes toward chemistry in general were sharply negative after taking organic chemistry. To address these two issues, we implemented POGIL activities in the course and the Science Writing Heuristic in the laboratory to replace the standard lecture format and verification laboratory experiments. This paper will focus on student performance on nucleophilic substitution reaction mechanisms on a class exam. Performance on these questions improved compared with students in past traditional classes. In addition, students were given a pre-class and post-class survey regarding their perceptions of the course. At the conclusion of the term, many students thought the class was easier than what they initially expected. This illustrates the view that non-science majors have the ability to learn organic chemistry from a mechanistic point of view, and integrate concepts learned in the laboratory with concepts presented in the lecture. (Contains 6 tables and 3 figures.)