How can I memorise chemical structures?

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Samson asked: I am try to learn the functional groups. I will be required to identify them in a complicated molecule and tell the ionisation of it. Here is an example:

I must be able to recognise that the molecule above is hidden inside the one below. I must also memorise that the red H will fall apart once the molecule is dissolved in water.

Incremental reading is for text. Occlusion will make the functional group become fragments in my mind. I don’t know what I am supposed to do. One subject in my next semester will mainly deal with functional groups and chemical structure recognition. Hopefully, Supermemo will make my life so much easier as it did for my Human anatomy subject.


Answer 1

Georgios answered:

1. Firstly, stick to the minimum information principle and do one thing at a time.

2. Secondly, think carefully about which parts you need to memorise and which parts you should always deduce on the spot in real life (because it's more efficient).

Here is an exemplary set of items to achieve your goals:


Q: What is the name of this molecule

A: phenol

Theoretically, this should actually be enough to recognise that molecule everywhere. You don't need to memorise what Donald Trump looks like going for a walk, giving a speech, handing out flyers, etc. It's enough to know his face and you can recognise him in many different situations.

However, for some added redundancy (i.e. to support the knowledge from another angle):


Q: Identify the phenol group in this molecule:


This second item ensures that you practice "lighting up" the part of your brain that recognises phenol, even when it's in a larger group. A bad item would be "What functional group is present here?" as there are several. Also, "Name all the functional groups here" simply does not stick to the minimum information principle. However, you could use this same image to ask "Identify the carbonyl group in this molecule:" and "Identify the hydroxyl group in this molecule:" too.

Finally, you want to learn that H will dissociate (i.e. fall apart) when dissolved in water;

ITEM 3 Q: How does this molecule react in water?

A: H+ dissociates

Obviously, you do not need to practice recognising that H+ will dissociate from the larger molecule too. That's where on the spot logic and thinking come into play instead. Also, as a final note, personally I would only highlight the H red in an image that shows upon clicking Answer. Having it in the question is probably too easy (because you won't normally have this cue in real life).

Answer 2

There are many similar cases described here:

How about:

  • What portion of the molecule X will separate when dissolving in water? (picture)
  • What molecule forms part of ...
  • What molecule can be used in the synthesis of ...
  • What molecule can be split off ...

Everything that you find in a textbook can be learned with SuperMemo. All skills based on a textbook learning can be learned with SuperMemo. All you need to figure out is how to convert knowledge and skills to the appropriate simulus-response connection.