How to Remember Stages of Reactions (Chemistry/Biology)


Have you ever found yourself panicking when your teacher asked you to draw the mechanism for the nitration of benzene? Or blanked on a test when you had to suggest the steps necessary to turn propane into propanoic acid? You are not alone with struggling with stages of reactions!

As a tutor, I have found that this style of questions tends to stump the average IB chemistry student. In this post, you will learn to harness the magic of active recall and spaced repetition to remember stages of reactions and ace your upcoming organic chem test! Even though this blog post focuses on chemistry, you can also use the techniques outlined below for physics, biology and more. 

1. Understand Curly Arrows

Not using curly arrows right is the downfall for many aspiring organic chemists. Therefore, I decided to dedicate an entire section to it! Double- and triple-check that you know what homolytic with a single arrowhead means. IMPORTANT: curly arrows always originate from electrons and indicate electron movement.

2. Create Puzzles!

Mechanisms can feel overwhelming in how complex they seem. There are so many moving parts that memorising them all can feel overwhelming. So, to help us along the path, we can (quite literally) break it into smaller pieces. We can turn memorisation into a game by creating puzzles! Here are a few examples that I recommend for organic chem.

2.1 Functional Groups

Let’s face it. We all have struggled to remember what an aldehyde was at one point or another. And what was the ending again? To help gain a firm grip on this fundamental of organic chem, I suggest you print out a sheet with all the functional groups & their endings. You can either find one online or look in your textbook! 

Print this out, and grab a pair of scissors – things are about to get fun! If you cut out all the pieces, you have a majestic chemistry puzzle on your hands. All you have to do now is store all the puzzle pieces in a box (make sure you don’t lose one of the brackets!). 

2.2 Mechanisms

If you look up the mechanisms in your textbook that you have to memorise, it can seem impossible. There are innumerable curly arrows and partial charges to keep track of – especially if you are an HL student. 

You can help yourself by breaking down all the individual pieces. First, draw out the mechanism in hand with plenty of space between the different components. Then, cut them out and see if you can get yourself to assemble them every now and then. Do this consistently and mechanisms will soon be your strong suit!

2.3 HL: Retrosynthesis: Memorising the “Pathway Tree”

How do you turn an alkane into a ketone? Which oxidising agents could you use? It is expected of HL students to know how to answer this question. To memorise all of these stages of reactions, it is helpful to refer to a “pathway tree” and create a puzzle from it. Here is an image of one to inspire you: 

3. Making the Puzzle Habit Stick 

So now that you have all the puzzles, you have to revise, revise & revise. Completing the puzzle will make you actively recall, so now you have to repeat this intermittently. Habits have an easier time sticking when you pair them with pre-existing ones. Could you maybe do one right after dinner every day? Before you brush your teeth? Or just after you come back from taking your dog for a walk? 

We have deconstructed complex tables and models and turned them into bite-sized puzzle pieces. Hopefully, this will help you optimise the memorisation process and remember the stages of reactions!

In case that you are looking for more ways to optimise your revision, check out our other blog posts here. It can also be productive to talk with an expert on revision. You can get in touch with one of our tutors here

Bonus tip: this works well for memorising VSEPR structures, too!

Written by Jascha Schäfer

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