Chemistry can be intimidating. As a subject that is a combination of physical sciences, life sciences, and some mathematics, its position as a "central science" makes Competitive Chemistry even more intimidating.

Surprisingly, being proficient at competitive Chemistry doesn't require you to be a genius. The amount of fundamental knowledge required in the field is much less in comparison to other Science Olympiads, and practice is more than enough to find success in your national exam, while still being a very enjoyable experience.

While this guide was written for the general public in mind, we do have specific guides that may be applicable to your situation. After fully reading this guide, we recommend you check them out.

There's no time to waste. Let's get started!

Part I: Before getting into Competitive Chemistry

Before you start, let's briefly talk about your mindset towards the competition. It might seem really silly, but I assure you, this is something you should put a considerable amount of thought on. There are some misconceptions and traps that a lot of people fall into and wonder where they went wrong, so we'll address them here, even before we talk about the competition itself.

Academic vs. Competitive

One of the biggest traps that newcomers fall for is the inability to differentiate the "academic" setting with the "competitive" setting. There are many meanings behind this, so let's talk about each one in detail.

An "academic" test that you take in school is very different from a "competitive" test you'd take in Chemistry Olympiad. Not only is the latter much more difficult, but they also heavily differ in terms of their goal. While the former tests on your mastery of the subject, the latter tests the extent of your ability to apply fundamental knowledge through problem-solving.

As these two totally different tests have different goals, you should not prepare these tests the same way. While you'd spend around three weeks at maximum preparing for an "academic" exam, the same is not true for the latter. On average, you'd be spending up to nine months preparing for your competition.

Now that we've got that clear, here are all of the traps you should avoid.

1. Do NOT overwork yourself

Pushing yourself is great and all, but overworking is very different from "pushing yourself". When people (and I) mean "push yourself", we mean it in a way that you should try problems that are slightly above your comfort zone, so that you can learn and improve. We do not mean you should overwork yourself and continuously cram three chapters of Klein's Organic chemistry reading, two national practice exams, and four chapters of Atkins' Chemical Principles every day.

Not only will you burn yourself out and hate yourself for getting into this mess, but it's simply not worth it because: 1) People who actually enjoy competitive Chemistry do much better than people who don't and 2) if you aim for completion instead of actually "understanding" what you learned, it won't matter at all.1

Competitive Chemistry should be a fun experience, not a painful one. Do yourself a favor and spread your work so that it's manageable. Take a lot of breaks, exercise, eat well, whatever makes you happy.

2. Do NOT overplan

Overworking and Overplanning are the two sins of Competitive Science. Overplanning is the act of planning what you'd do in the future (e.g. in 3 weeks). I and many others have tried out this strategy in the past (especially during summer breaks) and it has caused more harm than anything. Please keep in mind that humans can't foresee the future, and you never know if some concept will cause you trouble or get hit by a car. It is absolutely crucial that you don't overplan, as once you fall behind, you'll never be able to catch up and end up being demotivated.

3. Do NOT read college textbooks for Competitive Chemistry

If Overworking and Overplanning are the two sins of Competitive Science, then reading college textbooks is the grave sin of competitive Chemistry. This is crucial advice that everyone tends to ignore, so we'll repeat this many times.

A strong, first-year undergraduate general Chemistry along with Organic Chemistry is all you need to be proficient at Chemistry Olympiads.

No ifs, buts, or ands. Atkins' Physical Chemistry or Housecroft's Inorganic Chemistry will not help you in competitive Chemistry, at all. These are college-level courses that are not made for quirky smart high-school students like you2, and often require math skills above single-variable calculus. Let me repeat again:

A strong, first-year undergraduate general Chemistry along with Organic Chemistry is all you need to be proficient at Chemistry Olympiads.

While it is true that advanced topics such as physical chemistry aims to develop a better understanding of our chemical world, most, if not all, Chemistry Olympiads will not test your knowledge on something that can only be found from a physical or inorganic chemistry textbook. You should focus on mastering the fundamentals, as they are all you need to be proficient in this competition.

You'll need a strong foundational knowledge of the fundamentals to utilize what you learn from these advanced topics anyways, so don't bother for now.

A strong, first-year undergraduate general Chemistry along with Organic Chemistry is all you need to be proficient at Chemistry Olympiads.

4. Do NOT focus on textbooks

While preparing an school exam likely consists of doing some textbook problems, competitive Chemistry questions tend to be much more challenging than textbook problems (at least, in Chemistry3). While it is completely fine to review your fundamental knowledge through these textbook problems (and you should!), please avoid solving every single exercise and homework problem, as: 1) they'll get boring, 2) you'd be practicing plug-and-chug which is acceptable in an academic setting but unacceptable in an Olympiad setting, and 3) you'll be more vulnerable towards falling into deliberate tricks present in some Chemistry Olympiad problems.

5. Try to utilize all kinds of resources

A textbook isn't always the best place to learn, and this is especially true if your Chemistry Olympiad competition has specific "Advanced Topics" present that may be absent from the fundamental knowledge I've addressed multiple times above.

The best place to learn these topics are through our guides (work-in-progress), online lectures, ChemGuide, Wikipedia, etc.

Note: We are working on providing guides, notes, lectures, and practice problems for these "Advanced Topics", so stay tuned :^)

6. Don't be afraid

You know what's more scary than bombing your first exam? Not taking enough practice exams and bombing your real competition. It sucks, so don't do it.

Once you are comfortable applying your fundamental knowledge to homework problems, you should jump into practicing past exams right away!4 Unlike your high school exams (where past exams are often private), past exams of Chemistry competitions are publicly available.

7. Treat Competitive Chemistry differently

My final advice is this: you should (at least try to) enjoy your experience of both preparing for and competing in the Chemistry Olympiad.

In fact, there are more similarities between competitive Chemistry and video games in comparison to competitive Chemistry and academic Chemistry.

Consider this: When you start a new game, you normally go through a tutorial to learn about the rules. After absorbing the basics, you start playing the game. You find the game pretty enjoyable and want to get better, so you practice until you reach a point when you think you've reached a limit. You can tackle almost any situation that is given to you, but there are certain specific situations where advanced techniques could come in handy. So to become even better, you start to learn new strategies and advanced techniques that might aid you in certain situations.

This analogy can be applied to really anything: chess, speed cubing, learning an instrument, learning how to code, Lego, and of course, competitive chemistry!

Make sure to keep this ordering in mind, and take all the time you need until you get the hang of each step of the learning process!

I'd like to emphasize this one last time: Chemistry Olympiad exams tend to be very different compared to your regular Chemistry test in high school.

Unlike the chemistry you learn in an academic setting, competitive Chemistry will be challenging but also interesting, asking problems you've never considered or provide an unique scenario, requiring you to think and strategize.

I'd also like to emphasize this one last time as well: People who truly enjoy Chemistry Olympiad tends to do much better than people who don't.

Characteristics all Chemistry Olympiads share


Most rules for the National Chemistry Olympiads in different countries are structured similarly to the International Chemistry Olympiad (IChO). The largest requirement is age restriction. If the participant is over 20 years old after the July 1st of the year IChO is held, that individual cannot participate in the IChO. Therefore, it is very common that this restriction also applies to many national Olympiads.

Resources that are permitted varies a lot between countries. We highly recommend you conduct your own research on what your country allows, especially with calculator restrictions. The difference between a graphing calculator, scientific calculator, and calculators with built in CAS, and a four-function calculator are significant and we highly recommend you follow their standards. Here are the recommendations for each type:

  • Graphing Calculators: Any variation of TI-84
  • Scientific Calculators: TI-36X Pro, Casio fx-991EX (ClassWiz)

If your country permits a graphing calculator, they can be acquired cheaply from the secondhand market. However, many countries (including the United States) only permit scientific calculators and the administration will not allow you to use a graphing calculator.

Speed vs. Accuracy

Besides a fundamental knowledge, the Chemistry Olympiad heavily tests your ability of solving problems fast and solving problems accurately. Both of these features can be acquired by taking a lot of practice tests (experience) with a set time. As you will often be under a lot of time pressure, it is wise to develop a strategy in terms of time management before taking your national exam.

Here are some tips for developing speed:

  • If you don't think you can tackle a question, skip them for later.
  • You can skip through some "unnecessary steps" in your solution. Make sure anyone who has some knowledge of Chemistry can understand what you're doing, however.
  • Devise a plan in terms of the order of the questions you will be taking, assuming your national Olympiad has a concrete format.

While speed is a necessary component of the national Olympiad, it is highly recommended you work on problem-solving skills first rather than speed. You will not perform well if you manage to complete the exam, but make very silly mistakes in the process. Many of the national Olympiads are trying to trick you and fall into traps, so you must practice to avoid them even under high pressure.

Here are some tips for developing problem-solving:

  • Do not rely on the answer key. If you don't give much thought into the question and look at the answer key immediately, you will not develop a very strong intuition of chemistry problem-solving. The best competitors are those who can utilize their experiences to solve different problems, not those who can only replicate the solution.5
  • Read the entire problem slowly and carefully. While it sounds silly, David Morin's word says it best:

There's no better way to waste time than to read a problem quickly in an effort to save time. If you miss a piece of the given information, you'll end up just spinning your wheels, trying to solve an unsolvable problem.

  • There are many ways to approach a problem. You can try making approximations6, draw a diagram, reverse engineer, etc.


Mathematics skills are commonly encountered at the secondary school level, such as:

  • Solving qudratic equations
  • Using logarithms and exponentials
  • Solving system of equations
  • Basic trigonometry
  • Basic geometry (Pythagoras' theorem)
  • Basic statistics (plotting graphs, mean, etc.)
  • sometimes Integration and Differentiation (if it is included as one of the "Advanced Topics")

Most approximations in Chemistry are made when solving for variables. For instead, it can be very useful in certain scenarios where the Newton-Raphson approximation of solutions to functions apply and save a tremendous amount of time. For example, assuming A is many magnitudes larger than B, we can make the approximation that:

This is a very simple approximation that is widely used throughout chemistry, but there are more sophisticated approximations such as Taylor series that may be used.

Part II: Preparation of Chemistry Olympiads

The three steps you should take to prepare for your competition is this:

  1. Obtain a fundamental understanding of Chemistry
  2. Practice problem-solving
  3. Advanced Knowledge (Optional)7
  4. Profit

Obtain a fundamental understanding of Chemistry

There are many great textbooks and resources for learning the fundamentals of chemistry. Which one to use depends on your prior chemistry knowledge. Everyone starts differently; some may already have an appreciable background in chemistry (e.g. took AP Chemistry or have a background in physics), but others may have absolutely zero experience. Either way, I have a recommendation for everyone.

NOTE: You should read whatever your reading at least two times, to ensure you do not have holes in your fundamental knowledge.

For those with an appreciable physics background:

There are four types of forces you learn in physics: strong force, weak force, gravitation, and of course, electromagnetism.

Chemistry is a topic that revolves around the concept of electromagnetic force, and therefore those with an appreciable physics background will likely pick up chemistry much easier than others.

In fact, some of the topics you'll see in chemistry will be very similar (or exactly the same) to physics. This includes: thermodynamics, atomic theory, and gas laws.

Peter Atkins' Chemical Principles: The Quest for Insight is recommended for this group of people. Anything above 4th edition is perfectly fine to use. Even if you don't have any prior experience with chemistry, the Fundamentals section will provide you enough context to get through the textbook.

Different editions of Atkins textbooks

For those with an appreciable chemistry background:

If you took AP/IB Chemistry at school, Atkins' Chemical Principles: The Quest for Insight will be perfectly fine to start with. If you've just finished the course, it might be even possible to skip the Fundamentals section. If you haven't taken a chemistry course in a while, it may be wise to look at the Fundamentals section just as a crash course.

For those who have Chemistry 1 background or do not have a background in Calculus:

If you just took your first year of chemistry in high school, the book above might be a fairly challenging read, especially if you don't know any calculus.

Zumdahls' Chemistry is recommended for this group of people. Anything above 7th edition is perfectly fine to use. It's a much easier read than Atkins (textbook mentioned above), and covers a decent amount of fundamentals.

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It is highly recommended that you read Atkins after you complete Zumdahl's Chemistry for a stronger foundation!

For those who do not have a chemistry background:

This group of people is recommended to pick up Zumdahls' Chemistry. I'm aware that this might be a difficult read especially if this is your first time studying Chemistry, so Khan Academy is not a bad idea as a supplementary resource.

For those who hate reading textbooks:

With numerous amounts of open educational resources, there are many choices to choose from.

MIT 5.111 and UC Irvine's Open Chemistry course are two great choices in my opinion. Although they are not quite enough for a strong foundation, you can use our CODSnotes as a supplement to these lectures, or read the relevant sections of Atkin's Chemical Principles.

Taking Notes

Notes are a preference— you should take them if you’re used to taking them. If you do take notes, however, make sure you actually use them for review! If you don’t, the extra time spent on those notes would be meaningless. The CODSnotes written by myself are an alternative to taking notes on Atkin's Chemical Principles.

OK, so I've read Atkins.

Congratulations! You know more chemistry than 99% of people in the world! Give yourself a pat in the back.

Practice problem-solving

This is where you apply your fundamental knowledge to actual competitive Chemistry problems. Every competition is different, so you should read a guide below that is relevant to your situation. However, here are some general tips:

Writing Solutions

After grading many tests from CODS competitions, this is a tip especially relevant if you are solving a free-response problem.

You should think about how you want to present your solution to a problem before you start writing. Disregarding this step often leads to a confusing, unorganized solution. Make sure you're writing your solutions neatly with full sentences, so that the grader can easily understand your solution. Make sure your variables are properly defined so that any educated person can know what you're doing.

Make your solutions clear and legible. Don't let the pressure get to you and make illogical mistakes!

More Problem Solving Techniques

If you're interested in problem solving techniques, Problems and Solutions in Introductory Mechanics by David Morin is a fantastic book, especially if you're also interested in competitive physics.

Of course, the book itself isn't for competitive chemistry students like us, but the problem solving skills included are so valuable. Luckily, you can read most of the problem solving techniques at Amazon's preview.

Advanced Knowledge (Optional)

Recall that you should only be learning these after you have successfully completed the previous two steps.

Inorganic Chemistry

Miessler's Inorganic Chemistry: The textbook is compact, concise, and overall provides a decent introduction to the field, although some of its explanations are rather confusing and difficult to understand.
Housecroft's Inorganic Chemistry: The textbook is long, detailed, and very dense. Most of its explanations are simple, but it contains a lot of trivial knowledge that isn't required for the Chemistry Olympiads exam.

Organic Chemistry

Klein's Organic Chemistry: well explained, simple, introductory, focused on mechanisms. This is the only organic chemistry textbook that is truly required for Chemistry Olympiads, but might not be sufficient for competitions harder or equivalent to IChO.
Clayden's Organic Chemistry: Well explained, detailed, also focused on mechanisms, but also very well organized. This is one of the best books in the field of Organic Chemistry, but very overkill for most Chemistry Olympiads.
Advanced Organic Chemistry Textbooks: Carey and Grossman are popular, but these are often for graduates and you wouldn't be reading these textbooks for Chemistry Olympiads.

Physical Chemistry

Atkins' Elements of Physical Chemistry: well explained, decent introduction to physical chemistry, and doesn't go into too advanced mathematics. If you are truly interested in this field, you should check out this book. It is the middle ground between Atkins' Chemical Principles and Atkins' Physical Chemistry.
Atkins' Physical Chemistry: A typical Physical Chemistry textbook that is used by many colleges. Although it isn't very special. Not recommended. McQuarrie's Physical Chemistry: A Molecular Approach: This is infamously known to be one of the best physical chemistry textbooks to be ever written.

Analytical Chemistry

Harris' Quantiative Chemical Analysis: For an analytical chemistry textbook, it's a very decent book. It's great practice for advanced calculations (with good practice problems) and is a decent read.


Ok, if you've made it this far into the guide, first of all, thank you so much for reading this. Months of my colleague's experiences and my own personal experience were combined together to deliver this one heck of a masterpiece guide.

After you've gotten good at your nation's Chemistry Olympiad, you may wonder, is there any additional steps I can take, such as preparing for the international Chemistry Olympiad, or just trying out more challenging problems?

Question answered.

  1. And no, writing notes with your cram session won't "magically" make you remember everything.
  2. For more information in the role of advanced topics, you should read the Calculus Trap by Richard Rusczyk here.
  3. The one exception I can think of (with my limited knowledge) is physics textbooks. In particular, Red Morin and maybe Halliday.
  4. If your Chemistry Olympiad doesn't have any publicly available practice exams, you can either try out 1) Past exams of Olympiads that are known to be good quality 2) Past exams that have a similar structure to your nation's Chemistry Olympiad competition 3) Join our community and ask people who are competing in the same country as you.
  5. It is definitely OK to look at the solution manual when you are stuck, and you should (unless you really like a challenge). We are just recommending you not rely on the solution manual without giving it a proper shot.
  6. in very hard Olympiad questions, this might even be necessary to avoid solving insane equations on time
  7. We put advanced topics after problem-solving for many reasons. It is optional because you'll never use it 99% of the time; but we've added it here because these advanced topics are very interesting, especially when you actually have the capability to fully understand it.

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