AP Chemistry vs Organic Chemistry

A first post of sorts

Introduction

So this is the first post on this substack! I think making a first post dedicated just to be the first post is kind of strange (but still necessary, expect something of that style later) so instead, I present a blog post I wrote recently for another blog I have (which is also why this post may have some format quirks. (especially the LaTeX which I can not fix right now)). I feel as though this post is a good indicator of how I write and how I will approach topics in the future, so here goes!

Hate AP Chem? So do I! That’s why you should take Organic Chem, the class feared by many premeds! (Or just do USNCO)

Why AP Chem is a bad quality class

Is physics harder than chemistry?

I’ve written about this a bit on my own blog but this will be the first time I actually get a cohesive essay on it so here goes.

First off, I [i]kind of[/i] like chem so this is not a reflection of my experiences with doing horribly in the class but a more objective view of how the college board approached teaching general chemistry to high schoolers.

The problem with AP Chem is that it sacrificed continuity for content, thus making it easier than it should be. “Easy?”, you ask, “AP Chem is one of the hardests AP’s out there!” Touché, but I counter, which is harder, AP Physics or AP Chemistry? I argue that AP Physics is the harder course because its [i]conceptually[/i] challenging. If you memorize a bunch of equations in AP Physics you will struggle with the easiest questions because it was designed to be based off of intuition. Speaking from experience, you can not cram half the course in a few days and expect to skate off to a five, you need to know how everything interlocks. That is why having a math background is useful. (A contest math background especially) If you understand math really well then you have the intuitive grasp of physics because you can problem solve.

Returning to AP Chemistry we see a different type of difficulty. AP Chemistry is hard for the wrong reason. You [i]can[/i] brute force your way through AP Chemistry. It is not as conceptually difficult (relative to AP Physics) but instead just a HUGE amount of information. This is why I place AP Bio < AP Chem < AP Phys on the difficulty spectrum. AP Chem is still conceptually harder than AP Biology placing it above Biology despite Bio having even more information to [i]memorize[/i]. But it is still not extremely conceptually challenging, it only feels that way due to the fire hose of information given in a year. (Fun fact my school uses a block schedule, meaning we take 4 classes per semester and a normal class is just one semester, however AP Chem and Bio are both year long classes meaning we essentially get 1.5 years of instruction time.) AP Chem is difficult for the wrong reason, it ends up with people studying over lists and lists of information that may not seem to have any connection. You can get a five on AP chem without nearly as much conceptual understanding as would be required for a five on AP physics; therefore, AP Physics is the harder class.

The Firehose

This firehose is where I begin to have issues with AP Chemistry. [hide=(Note)], when I refer to AP Chemistry I mostly refer to the college board Chemistry Exam, however since most teachers teach the course to the exam this distinction may either be large (at a “better” high school) or small. We could make a whole other blog post on the problem with AP courses in general (the fact that the AP exam is not exactly meant to replace the actual college course) but that’s a post for another day. [/hide]

Collegeboard [i]could[/i] have included all that information while still designing the course to mesh well together. But that would increase the conceptual difficulty scale and make it way too hard. This is not specifically College Board’s fault, AP Chem is already regarded as a very hard course, but I do feel that it gives many people a negative feeling towards their first introduction to “proper” chemistry. In my opinion, making the course harder but also allowing for a richer understanding of the subject would be a net positive.

Treating (gen)Chem Properly

How can I confidently say that this would actually benefit AP Chem? Because I’ve seen that extreme, over the summer of 9th grade I took honors chemistry with Johns Hopkins CTY. The course teaches a lot of what AP chem does while not being afraid to keep the conceptual challenge high. This was my introduction to chemistry, all compressed into 2 months, what fun lol. The class taught all the same chemistry but in a different fashion. Instead of lists and blocks of things “you need for the AP test” you got lectures based off of building chemistry from Alchemy to modern era. The tests gave more AoPS style questions that forced you to actually understand why a chemistry concept worked in that sense. I remember for example, one question that told you to convert from Celsius to a new temperature system invented within the problem. This question required knowledge of how we treat dimensional analysis as a tool to fit together different systems (you solve that by doing an adjustment for the scale of one “unit” (imagine 100º C - 0º C = 212º F - 32º C) and for the scale of the “zero point” (again 32º F = 0º C). (Also if your planning on taking the course, warning, these tests are extremely hard and take a long time to complete.) This is not even chemistry and having that actual understanding of dimensional analysis may not be useful to most but it is a great example of how they payed attention to the conceptual aspect of the science. It was a much more enjoyable class than AP Chemistry was while being much, much harder.

Back to considering the AP

I now will cite specific ways in which AP Chemistry fails to give a good conceptual understanding of chemistry. We first start with the end, thermodynamics in the AP course. In this final unit you get a brief introduction to a very important concept in chemistry, $\Delta G.$ However it is squished into the end, treated as an extra piece of information right before review (cough cram) sessions begin for the AP test. What you do not get is the connection $\Delta G$ has to the rest of the course. You do not get any mention of how $K$ (the equilibrium constant) and $\Delta G$ are mathematically related ($\Delta G = -RT \ln K$), and why that is important. You only get to see it as a number which has the quirk of being able to predict spontaneity, whatever that even means. You do not see how the number arises as a tool built off of the basic laws of thermodynamics (some courses do introduce the derivation, but it is not required knowledge for the test). Let’s go back to $K$ for a moment. In AP Chem we treat Kinetics and Equilibrium completely separately, but that is not the full story. While yes, spontaneity does not actually imply a fast reaction, $K$ does relate to kinetics (in the form of $K = \frac{k_f}{k_r}.$). This is just a slight connection, but the connections become more important when you can consider how to derive thermodynamic equations by thinking in terms of Kinetics. (This is done in the Atkin’s textbook).

Sure, these connections (there are many more I have not put here, or even considered as “connections”) are not [i]required[/i] to understanding Chemistry but I do think they are important to gaining an [i]appreciation[/i] of the subject. They show that chemistry is not a memorization subject but a language. A language that can be understood and thus used as a way to describe new concepts without memorizing a list. We’ll return to this in the Organic chemistry toggle (and indeed in a few sentences).

Still, you may argue that AP Chem does still give you conceptual understanding. And yes, this is true, it gives you a minimum required amount. But it does not actively encourage this (again a difference between AP Physics (in a slight amount)), I remember a question on the AP chem MCQ last year that I was completely stuck on. It was on Beer’s law which I had decided not to look over. Missing this question would not have cost me anything but I was still annoyed at having to guess, until I remembered, the formula sheet! Two seconds later after flipping through a few pages I had the equation and nuked the problem. I did not solve it by any conceptual understanding on Beer’s law, I solved it by glancing at a formula. Let’s flip this to USNCO.

Chemical Competitions

Now we are stuck on a USNCO question. I do not see how the given information relates at all to one another. I think hard, wait, there’s an equation that can help! I flip back to the formula sheet and copy down the equation again, ready to go back and nuke with a plug and chug. Then I look back at the question, and realize its deeper than that. It’s not just solved by simple plugging in, I first need to solve for another value [i]then[/i] plug in. Do you see the difference?

Both the AP and USNCO question were ended with the application of an equation available on the equation sheet. But the USNCO question was not solve-able by just knowing an equation exists. It required you to know [i]why[/i] the equation exists, it required to connect the concepts of different AP chem units. You could solve the AP question by remembering the basic definition and formula, you could solve the USNCO question by understanding the foundation.

[hide=The type of USNCO question I had in mind while writing that]

[quote=Some old USNCO] The atmospheric pressure on the summit of Mt. Everest is 0.333 atmospheres. At what temperature (in °C) does H2O boil there? (∆Hvap H2O = 40.7 kJ•mol–1 ) (A) 71 °C (B) 87 °C (C) 96 °C (D) 98 °C [/hide]

hide=Ans This question ends with a plug and chug, but only starts with an understanding of the equation and vapor pressure. (It’s not the best example I could find but whatever).[/hide]

Here is an example of a purely conceptual USNCO question, one that is not too difficult. In other words, this is what AP chemistry could aspire to be:

[hide=2006 USNCO Part 1]

[img]https://i.imgur.com/VaH0QR4.png[/img]

So this question is fully within AP chem standards, and I think the strong AP chem student would easily get it. (Newer USNCO’s will use this sort of concept but build off of it a bit more). However it’s a very nice problem since it tests a student’s understanding of the meaning of $K_a.$ In the end it too is a simple plug, but it requires thought to why the ionization constant would work to give us the answer.

hide=Ans[/hide]

[/hide]

It’s a bit hard to comb through past tests to find examples but there are many other things that could be included. (Applications of equations like Clausius Clapeyron, Vapor Pressure concepts, and Systems of equations with dimensional analysis and stoichiometry come to mind).

I could, and might site more USNCO questions to drive this point but this is getting a bit long as is so we will pause there with the comp questions.

How a College Level Textbook approaches Chemistry

One note, I will be drawing this from my experiences with Atkin’s Chemistry, which is known to be more thorough than other genchem textbooks (especially as compared to Zumdahl, which is used at the AP Level (Zumdahl was the required textbook for my JHU CTY course) and College level). First off, the newer versions of Atkins are not arranged in chapters, but in “Focuses” (think of them as mega chapters) (there are about eleven focuses in the entire book). The way Atkin’s approaches chemistry is very similar in style to a math book. Everything is presented with derivations and reasoning behind choices made. It also makes sure to remind the reader that the Focuses are all connected, whether by the aforementioned kinetics and thermodynamics based derivations or a section devoted to explaining the connection. Atkin’s is a tough book to read without prior chemistry knowledge but it is more accurate to what chem can be.

In Summary, Part 1

That was a lot, but essentially AP Chemistry is not a good course because it prioritizes concept memorization over concept intuition. Looking at other approaches to chemistry, namely a high quality Honors Chem Course, USNCO, and a high quality chemistry textbook, shows us better ways of teaching the subject. AP Chemistry is difficult for the wrong reasons, the other examples are difficult for better reasons.

Part 2: How Organic Chemistry Fixes this

In part one we looked over just general chemistry as all of our cited examples were simply different ways of teaching introductory chemistry (or using it I guess). Now we compare general chemistry to organic chemistry, a more interesting proposition.

Language! - Steve Rogers

Earlier we likened chemistry to a language. I think the analogy works well. You have things to memorize, words and grammar rules among others, but you also have intuition (intuition can be thought of as math logic and non-math logic, we’ll refer to it as “syntax”.), in other words using the words to communicate. Our problems with AP Chemistry could be summarized by thinking of it as valuing the words over the communication. USNCO is more 42/58 word/syntax and I could see Atkin’s being more 45/55. AP would be 60/40 then. A higher quality general chemistry course could be approximately 52/48. Call this ratio the “weighting” of a course. (Also don’t treat the hard numbers as rule, more as a general idea of the course.) Now let’s take a look at an organic chemistry textbook titled Klein’s, Organic Chemistry as a [i]Second Language[/i], hmm see where this may be going?

Organic Chemistry is a very systematic study (my experiences are limited to Klein’s but I would be surprised if its drastically different among other courses), in it we can boil down everything to simply asking, what would the electrons do? (Yes, organic chemistry revolves around electrons just as much as carbon.)

Living up to the Stereotype

I think a lot of popular opinions toward chemistry would be in emphasizing the prediction of what two or more chemicals would do if mixed together. Just looking at general chemistry would lead you to believe that this is largely false. The closest general chemistry may bring you to [i]predicting[/i] a reaction would be solubility rules (you could make an argument for $\Delta G$ but that does not count as the products of the reaction are given already). This trend in general chemistry may be a source of why many don’t like chemistry. It makes the course look like its weighted much more to memorization than intuition. I think this is an unfair judgement on the course. The point of general chemistry is to teach you the language, it has to be weighted more to words than intuition so that the courses after it can go beyond. Above we did note that some approaches to general chemistry do weigh intuition over words but those are the exception. Also, those are all considered harder ways of teaching the subject, and most might require a prerequisite of a simpler chemistry course (Atkin’s for instance leads with a fundamentals chapter that basically condenses a high school regular Chem course into a chapter).

The weighing of Orgo

So general chem is inherently more weighted to memorization, with some courses (cough AP) leaning further than others. In my opinion, the weighting of Organic chemistry could easily be 40/60. (words/syntax) (Again these are just numbers I’m throwing out there to give an idea, for example what is the difference between 40/60 and 41/59? I don’t know.). In other words, it is much more intuition based than memorization based. [hide=Note]In practice this is not fully true because you do have to “memorize” a lot of information. In this case, treat memorization as trying to remember blocks of information with not much explanation. Then treat “memorization” as remembering the intuition behind something. This is a subtle difference but an important one, because most will tell you that Orgo is a lot of stuff to memorize. This is true, but the nature of the memorization is different.[/hide]

How it works in practice, a brief example

The more heavy intuition weighting relates to the stereotypical view of chemistry noted above, that most may think chem is about predicting the outcome of reactions. While this does not hold true for general chemistry, it basically summarizes the way Organic chemistry is taught. Time to cite examples, hurray! The first real dose you get of this during Klein’s is chapter 7, which goes over E2/E1 and SN2/SN1 reactions. (The preceding six chapters build the tools to allow the book to explain more precisely the behavior of the reactions).

Let’s quickly go over the basics of these reactions. The E in E2/E1 stands for elimination, in this case the removal of a halogen from a carbon. Removing a hydrogen from the $”\beta”$-carbon next to this $”\alpha”$-carbon then allows a double bond to be formed along the $\beta$ and $\alpha.$ E2 is the mechanism in which this reaction happens in one step (removal of the halogen and hydrogen, along with formation of the double bond). The two signifies that the reaction is bimolecular, meaning the two molecules involved (the carbon chain with a halogen and a strong base) both affect the kinetics (this is a 2nd order reaction to be specific). E1 is the same process except in two steps and we use a weak base.

The SN in SN2/SN1 stands for Nucleophilic Substitution. A nucleophile is simply a molecule with a region of high electron density, they can “attack” molecules with regions of low electron density (called electrophiles) in order to stabilize themselves. The substitution means that the nucleophile replaces (substitutes for) the halogen (or other group) which leaves the original carbon molecule. In other words, we have a carbon backbone with a halogen attached that is attacked by a molecule, kicking out the halogen. Similarly to the terminology of E2/E1, SN2 refers to the process being one step and 2nd order and SN1 as two steps.

Chapter 7 revolves all around these two types of reactions, importantly in how to predict what products will be produced when this reaction carries out. Predicting, not memorizing. You learn, for example, how to choose which $\beta$ carbon will lose a hydrogen for E reactions (regiochemistry if your interested). You see how the rates of an SN2 reaction change with the groups around the carbon to be attacked by the nucleophile. You get the tools to show when more than one product will be produced and which one will be present in higher amounts. The result is that you can take any two reagents (and their solvent $;)$) that could possibly undergo an SN2 and E2 and accurately predict what they will do together. Even if you have never seen these two molecules, provided nothing more complicated happens, you will know exactly what happens.

Also it’s worth noting how in each of these sections the role of electrons, whether by their presence, or their absence, have in explaining [i]why[/i] the atoms act in this way. This is the deepest layer of intuition that the entire text is built off of.

I’ll be honest I don’t know what to name this.

That was just one example but it is pretty representative of the overall book. If you would like to learn about this all in more detail or see more examples definitely check out Klein’s! Organic chemistry is all about knowing how stuff happens. AP Chem is all about knowing that stuff happens. These two different approaches may both have merits but in my opinion the former is much more interesting and cool. It might make Organic chemistry MUCH harder to learn, but it makes it feel relevant and offers a reward for true understanding of the subject.

Could this actually be applied to a general chemistry course though?

This is not a question I can easily think of an answer too. Obviously this was all based off of my own experiences and background so perhaps making a change like that would be a net negative (after all Orgo is still the bane of $\text{many’s}%wow sharp eye noticing this is LaTeX, I did it because the word was highlighted as a typo and it annoyed me$ existence).

I don’t think a general chemistry course fully based on the organic style would be very effective (unless for people already versed in the subject) because as noted before, you need to learn the words to understand the syntax. But certain parts of the course, for example Acids/Bases and maybe sections of Thermodynamics could very easily be adapted into a more intuition based approach. (It’s not a coincidence that Klein’s has a chapter devoted to acids/bases). In the end I’m not a chemistry teacher so that idea may have some fatal flaw I cannot detect.

A Conclusion

Well I don’t know if it required 3400 words, but yeah organic chemistry is much cooler than people give it credit for. I decided to make Part 2 shorter (Part 1 felt way too long upon retrospect) but I hope I showed a bit more on why chemistry is so interesting among others.