Students are notorious for feeling overwhelmed by the subject of organic chemistry. This leaves the instructor perplexed with the thought of effectively and adequately teaching the course. Often, the question posed is …
“…to use or not to use reactions?”
Both as a student and as an instructor, I have heard that students only feel that chemical content can be acquired through the act of memorization. However, I impress upon my students that they need to think of organic chemistry as a ballroom dance. I relate the topics of organic chemistry to a series of dance steps. Like a ballroom dance, the initial use of the new steps usually feels awkward and unfamiliar. Though, when applied, practiced, and combined, the basic steps become small movements, and the small movements are a transition into a complete and sophisticated ballroom dance. Likewise, when applied, practiced, and combined, the fundamental topics of organic chemistry are converted into sustained knowledge. With these metaphors, I hope that students can view reactions as helpful rather than terrifying. As an instructor, I emphasize that constant practice and the use of reaction mechanisms can help move organic chemistry content from short-term to long-term memory.
Organic chemistry is everywhere, and it’s driven by reactions. This is the exact reason why I teach the subject with reactions in mind. I teach students to identify organic species in the given environment, such as electrophiles, nucleophiles, leaving groups, acids, bases, and spectator ions. As each of these are introduced to the student audience, I present the species type with a known example and how all reagents (nucleophile, electrophile, leaving group, etc.) are incorporated into the appropriate reaction. Let’s look at the substitution reaction:
Words like electrophile or nucleophile tend to scare students and cause them to despise the process of learning a challenging subject. To remove the apprehension, I ask them to identify the organic species in the reaction.
- What is the nucleophile? How is it identified?
- What is the electrophile? Where is it located in the reactants?
- Which atom is the leaving group and spectator ion? Where are each of the atoms connected?
Once all the components are identified, I ask: “What’s the dance? How do the species move? What is attracted to where?” The answer is that the nucleophile moves to the secondary carbon, which was previously connected to the bromine, and the bromine leaves to generate the bromide ion in the product. I try to emphasize that the dance always goes “negative to positive,” or “electrons to positive.” I also emphasize that the conditions of the “dance,” or organic reaction, will stay the same, and if the reagents start neutral, then the reaction ends neutral.
Collectively, when I teach organic content in my class, I try teaching the mechanisms like a dance. By asking my students to view each step in the reaction as a singular movement, they transition away from memorization and towards the territory of true understanding. Using a text organized by mechanism, such as Karty’s book, allows instructors to teach students to look at electron movements only. Generally, students are apprehensive of mechanisms because of their names and numerous reagents. I try to compare the changes in these mechanisms to students’ switching out their partner in the dance. I explain to my students that the text is arranged by each type of electron movement, or should I say, each type of “ballroom dance.”
-Kerri Taylor, Columbus State University
Photo Credit: Library of Congress