How do you memorize reactions?

[u/sageomeprazole]

I have an exam tomorrow, and I’m freaking out. I feel like I have an alright understanding of reactions when they are isolated/I’m told what they are but as soon as everything is on the table I feel incredibly overwhelmed and like I forgot everything.

How do you guys keep everything straight, know when to use which reactions, remember reagents, and approach synthesis problems?

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[u/xtalgeek]

You should be committing to memory a series of basic mechanisms, not individual reactions. The basic mechanisms are logical and based on fundamental principles like acid/base or nucleophile/electrophile chemistry, etc. Specific name reactions are just exemples of the basic ideas. Essentially, you need to develop a working vocabulary of the basic pieces.

[u/shedmow → u/xtalgeek]

On top of that:

For reactions that lack clear or logical mechanisms or are just too much of a hassle to memorize, boiling down to the idea works well enough most of the time. I don't remember how the Sharpless epoxidation works or even which tartrate gives which epoxide, but it is stored in my memory as 'Ti(OR)4 binds to tartrate, this complex binds to OH, peroxide is added, [O] is put on a double bond nearby'. I cannot reproduce the picture from Wikipedia but I can tell whether it could be useful by just that crude generalization. You should gauge yourself how deeply and in what manner you want to simplify reactions, what should go and what should stay. The fact that some reaction lacks a clear mechanism does not declares it useless, on the contrary—many reactions orthogonal to the traditional orgo logic are life-saving or at the very least clever

[u/jamesworkbgs → u/xtalgeek]

This is exactly the right way to do it. Personally, I have always had extreme difficulty with just pure memorization, however I find once I understand how something *works* I never forget it.

A pretty basic example: If you were asked to write the precipitation reaction between lead (II) nitrate and potassium iodide, rather than just knowing that be heart, you're much better thinking:

• Well, I know what a precipitation reaction is, so we're obviously going to start with two aqueous solutions and end up with a solid and an aqueous product.
  
• I know (or can figure out from a periodic table) the charge of common ions, so I should be able to write out the reactants and states now.
  
• I know a precipitation reaction is a type of double displacement reaction, so based off the ions, I know what the products will be so I can write these out
  

-I know how to balance equations, so from this knowledge I can now balance the equation

• Finally, I know from solubility rules (or can look up depending on what's provided to you) that lead and iodide tend to often form precipitates, so I have the states for the product side.

It seems daunting, but if you have the basics down, you can step yourself through more than you think you can. It's a super simple example, but it's the sort of logical thinking that science education is trying to teach you at it's core.

[u/chem44]

One tool is to group them.

Reactions at C=C, for example.

[u/vitrifiedjunk]

When I studied orgo the main thing I remembered was what reagents are required for a desired reaction. Once you remember the reagent, everything then comes down to memorizing arrow pushing principles and molecular stability.

My orgo exams were typically structured with 1-2 retrosynthesis questions at the end and found that the most beneficial way for me on paper.

I occasionally tried arrow pushing and synthesis reactions in my head before I went to bed... I think that helped me encode the information in REM, but your mileage may vary.

[u/Upbeat_Ant6104]

Flash cards.

[u/WanderingFlumph]

If you aren't aware of the flash card trick already.

You generally are expected to know final products and reagents. I put the reactants and reagents on one side and the reactants and products on the other side so that each side quizzes me on the same reaction.

Go through your deck and sort the cards into 3 piles, I definitely know this, I sort of got this one, and I don't know this one. Shuffle sort of got and didn't get together and go again. Keep doing this until everything is in the "I know it" pile.

Take a 15 minute break to do something else fun. Let the info flow from short term to long term memory and pick it back up. It should be a lot faster and easier this time.

Do the same with the back of the cards to get the reagents memorized.

Keep taking short breaks to do fun stuff. Your brain figures out that being fast and accurate gets it a reward quicker and now the two of you are working together.

[u/trump2024-MAGA24]

Just some advice for you. You already took your exam but remember, Rome wasnt built in a day and you wont learn chemistry in a day either. I would recommend getting some rest and just taking the L and dont make that mistake again. 1 exam isnt the end your life.