Course: CHM303
Instructor: Semmelhack
F 2012

Description of Course Goals and Curriculum

The first semester of Organic Chemistry (Orgo) has several purposes, primary among them: to underscore the fundamental concepts informing the year long sequence, to teach the forms of (visual) representation used in the field, and to introduce the empirical methodologies of chemical isolation and detection. Lacking a formal syllabus, the course is loosely organized into three sections with each section/unit having its own two-hour exam. Each exam is cumulative, and the focus of evaluation is on the student’s ability to use chemical information creatively, synthetically, and rationally in response to new situations. That is, exams and lab reports rarely test the recall of information in lectures (the exams are open note, open book);the problems assume that students have a firm, working knowledge of concepts and fundamental facts and test how a student responds to material that is either new or presented in a novel way. Students must learn to recognize what they know (what may be “known firmly”), what they do not know, and how to determine the relevance of their knowledge in the context of new problems.

As a combination of theoretical principles, schemas of representation (formal drawings), and empirical facts, Orgo may be likened in some sense to learning a language. The first “unit” introduces acid/base chemistry of organic compounds (carbon containing molecules), the structure of bond orbitals (hybridization), and electron delocalization (resonance stabilization) all of which may be considered an essential “grammar” that informs nearly all aspects of the course for the rest of the semester and becomes increasingly critical for understanding the reactions explored in the second semester of the sequence. When the “course information” sheet states that students should “get help early” if they are struggling it is for this reason: the course is cumulative in that the principles of this “grammar” facilitate thinking one’s way through unforeseen contexts and nearly all subsequent material.

The second “unit” presents the four historical and contemporary means of determining the structure of organic molecules: mass spectrometry, UV spectroscopy, IR spectroscopy, and NMR spectroscopy. The course pivots in this second unit to explain the means by which these visualization techniques work experimentally and to teach the ways by which the data from these methods allow one to determine the atomic composition and structure of a molecule. During these lectures, it seems much of the information of the first unit is left by the side, but the problem sets and second exam stress a combination of the new material with the concepts introduced previously. Most loosely, the problems ask that one be able to interpret empirical data and provide rationalizations for the results based on concepts learned before.

The third “unit” completes the introduction to visual language/representation of Orgo by teaching the ways to draw cyclohexane rings and stereochemistry – the ways to render unique three dimensional structures in two dimensions. With this and the preceding two units’ of concepts, the course proceeds to chemical reaction mechanisms: drawn representations of rationalized understandings of chemical reactions. By the conclusion of the course, students are expected to work forward from reaction materials to a product, work backwards from a product to potential starting materials, and/or to fill in the intermediate stages between the two in addition to explain the concepts informing the reactions (e.g. how acid/base interactions, delocalization, structure, and solvent/reaction conditions are shaping the interactions).

Learning From Classroom Instruction

Lectures and precepts are not mandatory, but the instructors emphasize that exam material is drawn from lectures (and more explanatory precepts) than from the textbook. Partially completed lecture notes are provided prior to lecture for students to complete during lecture; the professor’s completed notes are posted later in the day after lecture.

Part of the difficulty in learning when (and what) assumptions are appropriate in problem solving may stem from what can (falsely) be interpreted as conflicting messages from instructors. Students may mistake statements like “the course is not about memorization” as an excuse to give up memorization-like work, or they may interpret “the textbook is reference material; the lectures are the source material for exam questions” as a statement authorizing them do less or no reading. Much of Orgo can seem so novel that students may doubt and neglect old, effective ways of approaching course material (like intensive readingand annotating of the textbook).

Consider what has worked best for you in the past, as this description may be excessive. Instructors list the chapters in the textbook that would correspond with the coming lectures in their lecture notes, but often it is too late to read before class as the lecture notes are posted only the day before class. As a result, it is useful to skim the chapters beforehand so that the lectures would not be a rush of new information (*at 8:30am in the morning in the fall, Orgo often is challenging in this regard too; many students even stop attending lecture as they find it a blur without proper sleep and preparation). While skimming, make chapter outlines – simply following chapter headings and subheadings, not copying any definitions or diagrams. During lectures, use the course lecture notes provided to follow along. Afterwards, as the first exam approached, use these two sets of notes – the chapter outlines and the lecture notes – and make a third set: a simplified synthesis of the two. Using the textbook, copy out by hand a few tables and diagrams that seemed more integral to the types of problems seen in problem sets and in class. Lectures provide a sense of what to copy from the textbook, but without looking at the textbook before hand, the lectures may have been too overwhelming./

Learning For and From Assignments

Each exam is cumulative, and the focus of evaluation is on the student’s ability to use chemical information creatively, synthetically, and rationally in response to new situations. That is, exams rarely test the recall of information in lectures (the exams are open note, open book);the problems assume that students have a firm, working knowledge of concepts and fundamental facts and test how a student responds to material that is either new or presented in a novel way. Students must learn to recognize what they know (what may be “known firmly”), what they do not know, and how to determine the relevance of their knowledge in the context of new problems.

In addition to the three exams that correspond to these “units,” there is a final exam, weekly labs and three lab reports, weekly problem sets (collected and marked “completed” but not graded), weekly precepts, weekly McGraw review sessions, and an abundance of practice problems since all past exams are available to students.

The textbook covers all the material in the fall section of the course but does not pose questions in the way that exams and problem sets do. The problems in Orgo do not conform to a simple format in which distinct variables may be cleanly isolated and set up in an equation. The analogy of a “language” is appropriate in this regard in that the principles and facts guiding much of the problem solving must also grapple with exceptions and irregularities. Students must develop the ability to recognize what is relevant when given on the context,  but this is not as straightforward as it may be with physics or general chemistry where one must determine which formula is appropriate. Rather, Orgo is somewhat “messier” in that variables and considerations must be weighed against each other either to determine a process, rationalize a product, or “intuit” a structure. Indeed, the emphasis of the course is to get students to the point of a “deep knowledge” in which “thinking like an organic chemist” becomes a matter of intuition rather than explicitly conscious frameworks or recall of facts.

The course mantra of “do more practice problems” may give the impression that practice problems alone will confer the knowledge and skills to do well subsequently. It is true that repetition and practice are crucial for success on exams, but without reflection, questioning, and working with the course texts (a combination of the textbook and lecture notes) it is more likely that each new problem will seem disconnected or unclearly related to those that came before.  Without doing more active synthesizing, even after doing numerous practice tests, students may receive their exam, check it against the key, and ask in confusion: “how was I expected to know that?!”

To counter this broad issue of accidentally bypassing Orgo’s conceptual foundations, I would encourage approaching the course “as if” all exams would be “closed book”.  Even if you prepare for (practice) exams with the goal of doing as much as possible without reference to notes or the text, something on the test will likely require you to consult a chart, table, or diagram etc. The exams are “open book” in this sense, that students should be able to wade into an unknown problem, make some headway before running up against a factual/empirical uncertainty, look up the information, then proceed with the problem. This type of understanding must be developed beforehand.

The single most effective practice I found (for myself and among other) to go about doing this is to make a personal, streamlined set of course notes . The calmest Orgo students I met brought their text books to the exams, but they most frequently referenced their† set of notes (not the textbook, and not the instructors’ notes available on Blackboard). The textbook or class notes might provide a necessary piece of information, like the relative acidity of Sulfur and Oxygen attached Hydrogens, but students’ personal notes serve as a master set or master reference students are more intimately familiar with having authored and ordered them.

External Resources

Engage with the TA’s!! Rather than spending entire afternoons stressed over one practice exam problem or lab report question, walk over to Frick to utilize resource center hours. The TA’s will explain any concept that may be confusing and will guide you to the answer without imposing on your learning process. Furthermore, while Prof. Semmelhack maintains a fast pace in lectures to cover the large volume of material, the TA’s have more time to focus on specific concepts and to elaborate on mechanisms that may be causing confusion. The TA’s were crucial to my experience in Orgo and I believe will be a valuable resource to future students.

What Students Should Know About This Course For Purposes Of Course Selection

Orgo offers what is for many a radically (and exciting) new way of thinking about the world and biological organisms. Even as students stumble through the course, they do develop a distinct form of critical thinking, one that pushes past rote pattern recognition to a lighter sense of comparing and contrasting probable causes and effects. Additionally, and more concretely, students learn to depict the world of organic chemistry—they learn to the system of lines, dots, letters, and arrows that make up Orgo’s visual vernacular.

The course feeds directly into the second semester of Orgo which is offered in two sections: one with a biological emphasis and the other with a focus on synthesis of organic molecules. Both are intimately dependent on the concepts in the fall, and both spring courses end up covering the same broad concepts and reactions but explore them differently.

Organic Chemistry I: Biological Emphasis

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