“Learn the concepts! Don’t memorize!”.
It’s one of the most common sentences found in the many examples of instructors’ essays on “How to Succeed in Organic Chemistry”.
But what does it really mean? It took me a long time to figure that out. But I’m going to try to explain it with an example.
Let’s take two students with different study strategies.
One of them focuses on memorizing facts, reactions, and numbers.
The other one focuses on understanding the trends that lie behind those facts, reactions, and numbers.
They’re given a test with a question like this one:
Which strategy will do better? The student who focused on memorization would have known from a pKa table that alkynes are more acidic than alkenes, which are more acidic than alkanes. The second student, knowing acidity trends, would be able to recognize the fact that the hybridization of the carbons in the alkyne, alkene, and alkane are sp, sp2, and sp3 respectively, and would know that acidity increases as you increase the amount of s-character in a bond since the electrons are stabilized by being closer to the nucleus.
Both memorization and a concept-based approach would work for answering this question. The difference is time: It takes longer to gain an understanding of what is going on rather than just memorizing a group of numbers. Last-minute crammers, understandably, go for the memorization approach.
Now change the question to either one of these two:
Who will do better now? This type of question will destroy the memorizer, because you won’t find values for these acidities in textbooks. It’s just too obscure. However, the student who focused on learning the concepts could answer this question without having put in additional time to study – because it involves applying the same concept that was applied in the first question. **(note at bottom)
There are definitely organic chemistry courses where the instructor favors a pure regurgitation based exam style. If you’re taking a combined one-semester course in organic chemistry with little to no focus on mechanism, a pure memorization approach might actually work.
However, at a more advanced college level, instructors will have higher expectations and have developed testing strategies designed to thwart memorizers.
In short, while memorization might be effective for you if time is short, it is a fragile strategy that can easily be beaten by a professor who is intent on testing concepts.
** note on these questions: since acidity increases as you go from sp3 to sp2 to sp, basicity will *decrease* as well. So sp-hybridized oxygen is less basic than sp2 hybridized oxygen which is less basic than sp hybridized oxygen.