You may have heard that studying organic chemistry is a total nightmare. However, organic chemistry is actually not that difficult by any means. Having adequate knowledge of the prerequisite courses of organic chemistry and understanding how organic chemistry works, in general, will enable you to study reactions and reaction mechanisms in organic chemistry with little effort.
The key to studying organic chemistry and reaction mechanisms is to avoid memorizing. Instead, you should understand how organic chemistry reactions work to be able to identify the correct reaction mechanisms when needed.
If you have trouble memorizing or understanding organic chemistry reactions, we’ve got you covered. In this article, you’ll learn more about the main types of organic chemistry reactions and different reaction mechanisms. To make things even easier for you, the article provides a detailed step-by-step guide to learning and memorizing organic chemistry reactions.
Main Types of Organic Chemistry Reactions
Before you even try to memorize organic chemistry reactions, you should learn more about the types of organic reactions and how they work.
There are four main types of organic chemistry reactions, including nucleophilic substitution, electrophilic addition, elimination, and rearrangement reactions.
To understand how organic reaction occur, let’s define a few key terms:
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- Nucleophile (Nu:) – A nucleophile is an electron-rich species (a Lewis base) that can easily donate an electron pair and form a new bond.
- Electrophile – An electrophile is an electron-deficient species (a Lewis acid) that seeks to accept electrons and form a new bond with a nucleophile.
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- Leaving Group (LG) – A living group is a species that takes a pair of electrons with when it detaches.
- Substrate (R-LG) – A substrate is a reactant of a reaction that is being chemically modified. To be a substrate in a nucleophilic substitution reaction, a molecule must have a good leaving group.
Check out this video tutorial by The Organic Chemistry Tutor to understand the basics of organic chemistry reaction types.
Here’s what you need to know about the main types of chemical reactions in organic chemistry.
Nucleophilic Substitution
Nucleophilic substitution is one of the essential types of reactions in organic chemistry. In a nucleophilic substitution reaction, a nucleophile attacks an electrophile and replaces the leaving group.
For detailed information about nucleophilic substitution reactions, check out this video by ChemSurvival.
Electrophilic Addition
Electrophilic addition is another fundamental organic reaction. In an electrophilic addition reaction, electrophilic and nucleophilic components are involved. A great example is the addition reactions of alkenes, the chemical transformation of a carbon-carbon double bond.
To understand how electrophilic addition reactions work in alkenes, check out this video by Eliot Rintoul.
Elimination
Elimination reactions typically occur in saturated organic compounds, those with single carbon-carbon bonds. Elimination reactions are the most commonly used reactions for synthesizing alkenes from alkanes. In an elimination reaction, certain fragments from adjacent atoms of a reactant molecule are eliminated (removed).
The Organic Chemistry Tutor explains how elimination reactions work by discussing the formation of alkenes from alkyl halides and alcohols.
Rearrangement
Rearrangement reactions occur when constituent parts of a molecule are reorganized. In other words, in a rearrangement reaction, the carbon skeleton of a given molecule is rearranged, producing a structural isomer of the original reactant.
Professor Dave explains how carbocation rearrangement works by providing examples involving hydride and methanide shifts.
Reaction Mechanisms in Organic Chemistry
What makes memorizing organic chemistry reactions relatively challenging for some students is understanding reaction mechanisms.
A reaction mechanism is a step-by-step path by which reactants are transformed into products. To write mechanisms in organic chemistry, you’ll need to show the movement of electrons by drawing arrows.
Writing organic chemistry reaction mechanisms can be pretty straightforward as long as you understand the basics of how to do it. Explore this video by Leah4sci and learn based on the reaction mechanism pattern examples.
A Step-by-Step Guide to Memorizing Organic Chemistry Reactions
Studying and memorizing organic chemistry reactions can be pretty straightforward as long as you know how to get started.
To memorize organic chemistry reactions, you should first realize that memorization is not something that would help you understand how the reactions work. Besides, you should try to write every reaction mechanism down instead of staring at your textbook. In addition, you should ensure that you understand how a given organic reaction works before you move to the next one. To deepen and broaden your understanding of organic chemistry reactions and mechanisms, ask questions, use online resources, attend lab sessions, and keep practicing.
Here are a few steps to follow to not only memorize but also understand different organic chemistry reactions and reaction mechanisms.
Step 1. Avoid Memorizing Reactions and Reaction Mechanisms
If you want to memorize organic chemistry reactions, you should realize that memorizing is not what you should be aiming for. While memorizing certain concepts and rules of organic chemistry could definitely help you increase the upcoming quiz or exam score, this is not something that would work in the long run.
When memorizing organic reactions, you’ll most likely forget the key aspects in a couple of days. This is exactly why teachers and professors recommend avoiding memorization. No matter how good you are at learning chemistry by heart, it won’t work in the case of organic chemistry reactions.
Step 2. Understand How Chemical Reactions Work in General
Knowing the basics of chemistry and chemical reactions will allow you to learn organic chemistry reactions with little to no memorization. This is why general chemistry is among the prerequisite courses of organic chemistry. If you don’t have sufficient knowledge of general chemistry, you’ll most likely have trouble understanding both basic and advanced concepts of organic chemistry.
So, understanding the rationale behind chemical reactions in general is absolutely crucial for taking a step forward to learning organic chemistry reactions. If you feel like you don’t really have adequate knowledge of general chemistry, it’s probably the best time to invest your time in studying and create a revision plan.
Khan Academy provides an introduction to chemical reactions and here are the main types of chemical reactions.
Step 3. Learn More About Reaction Mechanisms
The next step is to learn more about the basics of reaction mechanisms in organic chemistry. Along with being able to draw arrows that indicate the movement of electrons, you should also have sufficient knowledge to determine the number of steps in which a given chemical reaction occurs.
While reaction mechanisms may seem a bit confusing at first glance, you can easily master the technique of writing mechanisms if you do your best to understand how everything works instead of memorizing.
Although you can use your textbook to get started, paying attention to presentation slides during lectures and watching YouTube tutorials will help you a lot.
Step 4. Write Everything Down Instead of Staring at Your Textbook
One of the most common mistakes organic chemistry students make is reading their textbooks over and over again. No matter how many times you read a given chapter or for how long you stare at a specific reaction mechanism, it simply won’t be enough. Instead, you should consider switching to an active form of studying.
The key to memorizing organic chemistry reactions is writing everything down. Whenever you see a reaction mechanism, take a notebook and write it down. This will help you a lot because staring at compound names, molecular structures, and reaction mechanisms in a textbook might make sense at that given moment. However, you may not be able to connect what you saw in the textbook with the question you’re being asked.
Step 5. Learn How a Given Reaction Mechanism Works Before Moving to the Next One
Another tip that will help you understand organic chemistry reactions is to focus on a specific reaction and mechanism at a time. Writing a given reaction mechanism just once and moving to the next one may lead to confusion. Instead, you should take your time to understand how that particular organic reaction works before continuing with another one.
Keep in mind that it may take a few minutes or even hours to fully understand the rationale behind a given reaction mechanism in organic chemistry. Just don’t give up!
Step 6. Ask Questions and Use Online Resources to Deepen Your Understanding of Reaction Mechanisms
For numerous reasons, students are often afraid to ask questions in front of the whole class. In fact, asking questions increases curiosity about a given topic and curiosity helps you learn faster. Besides, asking questions allows you to gain a better understanding of that particular topic, making it much easier for you to study at home.
Another factor that significantly boosts your overall performance is using online resources when studying. If there’s something you can’t really comprehend or you just want to learn more about a given topic, you should refer to scientific articles or video tutorials available online.
When it comes to studying organic chemistry, The Organic Chemistry Tutor is one of the absolute best options. His educational videos are comprehensive and easy-to-understand at the same time.
Step 7. Avoid Skipping Organic Chemistry Lab Sessions
I know that attending at least 3-hour lab sessions can be exhausting and frustrating sometimes, but trust me, organic chemistry experiments are extremely educational and fun to conduct. Besides, lab experiments allow you to better understand how certain chemical reactions work.
If you have trouble memorizing organic chemistry reactions, being able to visualize what’s actually going on when mixing different organic and inorganic compounds will make things much easier for you.
Step 8. Be Prepared for Organic Chemistry Lab Sessions
Along with attending organic chemistry lab sessions, you should arrive prepared for the experiments. This involves writing a pre-lab report and getting a better idea of what experiment you’re about to conduct prior to walking into the lab.
Being prepared for a lab session is pretty much crucial for understanding the steps of different chemical reactions. And this will significantly boost your understanding of organic chemistry, making it much easier to memorize O-Chem reactions.
Step 9. Keep Practicing
Last but not least, you should keep practicing. Even if you feel like you’ve already memorized a given reaction mechanism, the chances are that you’ll forget it soon. To avoid this, especially right before an exam, you should schedule revision sessions to practice.
While flashcards can be used for revising theoretical aspects of organic chemistry, they aren’t quite helpful when it comes to organic chemistry reactions. This is because 2-D flashcards don’t actually show how organic reactions occur. Instead, try writing reaction mechanisms a few times to make it easier for your brain to process the information.
