Most points on Organic Chemistry exams are lost in weak areas that are highly preventable, i.e. areas requiring a constant "workout." I've been keeping a mental tally for over ten years on where errors are routinely manifest, how they're made, and how such errors can be avoided. You can read this article in less than five minutes, apply what is discussed, and increase the score on your next exam by a percentage directly proportional to the amount of energy you invest in strengthening certain areas.
7 Workout Areas in Organic Chemistry
1. Confusing oxidations with reductions, using oxidizing agents such as PCC to reduce carboxylic acids, and using LAH to oxidize alcohols. This happens more frequently than anyone might imagine. There are two ways to avoid this trap. First, understand the oxidation states of carbon, and know how to calculate them. Second, make compound cards for all "letter reagents" such as PCC or LAH, being certain to indicate on the backs of such cards the structure and reactivity of the reagent. Also, understand that an oxidation is a loss of electrons to an oxidizing agent, and that a reduction is the gain of electrons from a reducing agent.
2. Losing skills in drawing Lewis structures. This becomes highly influential on exam scores beginning around week 15 of Organic Chemistry when electrophilic aromatic substitution is introduced as a topic. The reactions are easily memorized, however the mechanisms are not, and require the ability to draw highly relevant Lewis structures for every functional group.
3. Losing skills in resonance and drawing resonance structures. Arguments in Organic Chemistry are based in sterics and/or electronics, and resonance falls within the electronic category. Aromatic chemistry, electrophilic or nucleophilic, is understood when resonance is understood. Likewise, understanding resonance is necessary for learning and applying carbonyl chemistry.
4. Losing skills in understanding acid-base equilibria, what's a strong acid and what's a weak acid. Just as 95% of Organic Chemistry is explained by a nucleophile going after an electrophile, it's also explained by a Lewis base going after a Lewis acid, hence 95% of Organic Chemistry is Lewis acid-base chemistry. This was the reason for learning the concepts in week 2.
5. Confusion about what's the nucleophile and what's electophile in the reaction. Of paramount importance, the most nucleophilic center must be identified, as so must be the most electrophilic center. It's better to master these subjects early. After week 20, many molecules will have multiple nucleophilic and electrophilic centers, and a weakness in identifying such centers will lead to total confusion.
6. Understanding retrosynthetic analysis. This is the area wherein students lose the most points. Most of us are auditory-sequential learners who excel at performing tasks in a forward-thinking linear sequence. It just so happens that the synthesis of complex organic compounds are not amenable to this type of thinking. It's crucial to learn to think backwards as early as possible, to confront the discomfort and frustration head on (we're talking about your ticket to professional school here!), to struggle and then conquer. Avoidance of retrosynthetic analysis will not make it go away, rather tackling it head on will lead you to mastery.
7. Remaining comfortable. The first time I used this phrase was on a friend in graduate school who couldn't understand why he was unable to surmount a problem. Somehow, I realized in 1988 that the key to success in life was in becoming comfortable with being uncomfortable. Please think about this statement for a few days, and you'll understand the wisdom that some people never learn in a lifetime. When you're struggling and uncomfortable, you're really learning!
7 Workout Areas in Organic Chemistry
1. Confusing oxidations with reductions, using oxidizing agents such as PCC to reduce carboxylic acids, and using LAH to oxidize alcohols. This happens more frequently than anyone might imagine. There are two ways to avoid this trap. First, understand the oxidation states of carbon, and know how to calculate them. Second, make compound cards for all "letter reagents" such as PCC or LAH, being certain to indicate on the backs of such cards the structure and reactivity of the reagent. Also, understand that an oxidation is a loss of electrons to an oxidizing agent, and that a reduction is the gain of electrons from a reducing agent.
2. Losing skills in drawing Lewis structures. This becomes highly influential on exam scores beginning around week 15 of Organic Chemistry when electrophilic aromatic substitution is introduced as a topic. The reactions are easily memorized, however the mechanisms are not, and require the ability to draw highly relevant Lewis structures for every functional group.
3. Losing skills in resonance and drawing resonance structures. Arguments in Organic Chemistry are based in sterics and/or electronics, and resonance falls within the electronic category. Aromatic chemistry, electrophilic or nucleophilic, is understood when resonance is understood. Likewise, understanding resonance is necessary for learning and applying carbonyl chemistry.
4. Losing skills in understanding acid-base equilibria, what's a strong acid and what's a weak acid. Just as 95% of Organic Chemistry is explained by a nucleophile going after an electrophile, it's also explained by a Lewis base going after a Lewis acid, hence 95% of Organic Chemistry is Lewis acid-base chemistry. This was the reason for learning the concepts in week 2.
5. Confusion about what's the nucleophile and what's electophile in the reaction. Of paramount importance, the most nucleophilic center must be identified, as so must be the most electrophilic center. It's better to master these subjects early. After week 20, many molecules will have multiple nucleophilic and electrophilic centers, and a weakness in identifying such centers will lead to total confusion.
6. Understanding retrosynthetic analysis. This is the area wherein students lose the most points. Most of us are auditory-sequential learners who excel at performing tasks in a forward-thinking linear sequence. It just so happens that the synthesis of complex organic compounds are not amenable to this type of thinking. It's crucial to learn to think backwards as early as possible, to confront the discomfort and frustration head on (we're talking about your ticket to professional school here!), to struggle and then conquer. Avoidance of retrosynthetic analysis will not make it go away, rather tackling it head on will lead you to mastery.
7. Remaining comfortable. The first time I used this phrase was on a friend in graduate school who couldn't understand why he was unable to surmount a problem. Somehow, I realized in 1988 that the key to success in life was in becoming comfortable with being uncomfortable. Please think about this statement for a few days, and you'll understand the wisdom that some people never learn in a lifetime. When you're struggling and uncomfortable, you're really learning!
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