Editor (fizzest)'s note: This guide was written by Allen Ding, one of the IChO alternates for the USA 2019 IChO team. He was very kind to giving me permission to upload this guide on the CODS website. To preserve the original writer's words, I have only made formatting changes to the overall guide. You can read the original here.
Lab is a very difficult portion of the USNCO/Camp/IChO competition partially because it’s actually hard, but mostly because most people don’t have much experience with it. It’s also kind of a big meme that the USNCO labs are the literal opposite of what you’re given at camp and IChO- USNCO throws lab problems that you must devise a procedure for, while higher levels give you the procedure and you just have to do the lab. Despite the fact that this sounds much simpler, it is significantly more difficult since higher level techniques and skills are involved. However, it is essential to know how to perform lab well- it is just as important as theory and requires much more practice.
Don’t be discouraged though! In this nifty guide, I’ll do my best to give some pointers and advice on how to get better at lab.
So basically, this list categorizes different lab skills at camp/IChO level by usefulness.
This list categorizes skills by difficulty to do.
The lab format for IChO differs from year to year, since the preparatory problems are very different each year. However, the two things that are pretty much always tested are organic synthesis and titrations. Not surprisingly, these are the 2 most difficult skills to execute and master, even though they both seem super simple.
On top of that, there’s usually some other fun stuff that’s throw in yearly, typically involving some lab involving absorbance, equilibria, kinetics, or qualitative analysis. These are typically easier and people are usually more comfortable doing these compared to the ones up above.
I’ll also talk more about how to do both USNCO and IChO labs later in the guide.
Listed below are a couple of very, very important skills that are covered in depth. All of these skills play together, and you will definitely need each one working together in order to perform well. Most of these are focused on what you’ll need at the international level, but are also very critical for nationals as well.
Just like you got good at theory, getting good at lab, at the very core, requires you to practice a lot and get comfortable with what you’re doing. You shouldn’t expect to be able to ace a lab if you haven’t run it before- in fact, even finishing the lab without practicing it before is difficult. This is why I recommend that, if you really want to get good at lab, you should have a home lab so that you can run experiments multiple times and see what works best.
Experience in the lab is what will differentiate chemists. With more experience, you’ll know where you can cut certain corners or where you should pay more attention. Simply put, you’ll know what exactly it is that you’re doing- being confused in the lab will seriously take away from your time and also screws up your mental game. Practicing will provide familiarity with the lab equipment, proficiency with handling glassware, and a general sense of knowing what you’re doing and how to think.
So how exactly does one practice? Well, like I said before, the most straightforward answer is to get a lab yourself. However, this is not exactly the most viable option and thus the second way would be to practice at school. Consult with your chemistry department and see if you can get some experiments set up- most schools should have the proper glassware and reagents to run IChO labs, as well as a fume hood so you can really get the whole experience. A lot of it is about getting your hands used to lab work- even the simplest of techniques, such as how to properly perform a titration or handling glassware, are skills that not many people possess when they begin. If you’re not able to run experiments due to lack of reagents or your chemistry department being jerks, practicing with water is actually a very good way to get the feel of things. Perform titrations with water. Make stock solutions with water and food coloring. Transfer liquids using water. You can literally do anything with water, and when it comes to actually using the techniques with actual chemicals, you’ll know how to do it.
Also, apparently baking/cooking is a legit strategy since it’s pretty much the same thing as lab- follow instructions using the proper equipment. So I guess if none of the above work and you’re really desperate, this is also an option.
At the International Chemistry Olympiad, you’re given 5 hours to perform 3 labs. This sounds like a lot of time, but it really isn’t and there’s absolutely no way you can do them linearly and expect to finish. You’re going to have to perform labs simultaneously, using every second productively. If you slack off for a couple of seconds or minutes, the additive effect is devastating. Make every second have a purpose.
The easiest way to finish things on time is to read all the labs, set up a mental plan, and then just take off. There’s no time to turn back, and there’s certainly no time for mistakes- so read the labs well because once you screw up, you will most definitely have to alter your plan and your mental game will be wack. Always start with the organic synthesis lab(s) first, since it’ll probably look something like this (albeit a bit more detailed), and it makes absolutely no sense to start it anytime other than at the beginning:
Add x, y, and z into a round bottom flask, add a magnetic stir bar Turn on the hotplate, attach the round bottom to a condenser, and reflux for an hour
The entire way you approach the lab practical and concoct a plan should be based off of the longest lab, which will pretty much always be the orgo. Since the steps usually require a lot of waiting, you should be doing the other 2 labs within these steps. You should most definitely be thinking ahead, estimating what you can get done within that time and executing them quickly but precisely. Essentially, you should have all 3 lab procedures going through your mind simultaneously, shifting focus between each one and keeping track of when you should start a step, and when one’s about to end.
Unfortunately, it’s very difficult to think in this manner if you don’t practice. 3 labs will be very intimidating, and if you start to panic you’ll want to focus solely on one and neglect the others. That’s why you have to get comfortable with working in this style, since time management is impossible without experience and confidence. For example, if you make a tiny slipup, you’ll probably think about it for the rest of the lab and lose focus of the task at hand.
Additionally, getting experience allows you to bend time to your own liking in two ways. The first is that you don’t waste any time on very small things, which will always add up to a lot of time lost. Say, for example, you’re preparing to make a solution, but you have to spend a minute or so figuring out how the pipet bulb works. Then, you realize you should probably start the next step of another lab, so you quit making the solution and start the next step of a different lab, which requires a 100 mL beaker but all of yours are being used. So you go back to making the solution, when you realize you left your orgo lab refluxing for 15 minutes longer than you should have and now you’re panicking to remove the round bottom flask since it’s too hot, so you leave it on to cool. 10 minutes have passed and you’ve gotten absolutely nowhere except for figuring out how to use a pipet bulb, and the fact that your hand hurts since the round bottom burned you.
All of that can be avoided by practice, in which case those small slip ups won’t occur and you’ll always be on top of things. It also segways nicely into the second way to excel at time management- using your time super efficiently. Once you get the feel of things, you’ll know precisely the order things should go in, when you can push off finishing a step to do something else, and many other small decisions that ultimately save you time. Furthermore, a part that a lot of people tend to overlook are the post lab questions, since they’re sneakily hidden in the very back, far far away from the procedure. If you ever find yourself waiting, you can always see if you’re able to answer a couple of them before you forget- your lab means absolutely nothing if you don’t have anything written down on paper. When it comes to the whole making shortcuts part, however, let’s consider the following scenario. Let’s say that your reflux has about 5 minutes left, and doing any part of another lab would require 15 minutes, you don’t have any post lab questions you can answer, and you won’t have time to worry about your synthesis. There are 2 choices, really- wait 5 minutes for the reflux and move on, or do the 15 minute step first. The initial instinct will be to follow every direction 100%, so you’ll wait 5 minutes sitting around and twiddling your thumbs. However, after enough practice you’ll realize that refluxing for an extra 10 minutes doesn’t actually matter and is probably more helpful than detrimental, so the second option is much better. So instead of losing 5 minutes, you’ve occupied that time to the best of your ability- It’s small tidbits here and there that give you time to do more things. I
Finally, you must always conduct multiple trials. It’s not explicitly stated anywhere but it is an absolute must. This is, however, only possible if you have enough time to do them; you’re never truly “done” with a lab until you’ve turned in your paper. So if you’ve “finished” a lab and you’ve got a couple of minutes, run another trial for more data. Maybe you’ll find a mistake in your previous data that you can correct, or you have more evidence to back up your conclusion. Overall, running additional trials is something that must be done without question and should be factored into your plan for how you’re going to spend your 5 hours.
Like it does with pretty much everything else in the world, the mental game can completely make or break your chances. Even if you make a horrible, terrible mistake, you gotta just keep on moving and start over. It’s easy to want to tell yourself “man this sucks”, give up, and clean up with 2 hours remaining. And even if you don’t do that, you have to manage to stay focused and finish things calmly, as difficult as it might be. Because once you’re not focused and completely out of the loop, you’ll lose track of what you’re doing and only continue to botch up, which will cause you to tilt even harder. It’s a vicious, never ending loop, but once again, the solution is a lot of practice. When you practice a lot, you’re bound to screw up a lot as well; thus, you eventually build up a tolerance to it, and how to continue even after making a mistake.
Doing the labs with confidence also means that you won’t waste time second guessing yourself or staring off into the hood contemplating your choices. It also means that you won’t find yourself looking at how other people in the lab are doing- in fact, you should never do this since it never helps. When it comes to comparing yourself to others in the lab, there are a couple of outcomes that can occur, none of which are particularly helpful:
The bottom line is, don’t compare yourself to others in the lab. Stay confident throughout and don’t lose your cool, cause then you lose the game.
This is a big one. You can run through a lab not really knowing how to do it at all, and as long as you’re not being dumb, you’ll get somewhere. The thing is, there are infinitely more ways for something to go wrong in a lab than for something to go right. Typically, things only go wrong either by sheer accident or if something really, really stupid occurs. And it’s usually the latter.
In all seriousness, it’s important to keep your brain on and alert throughout the entire lab, even though it’s super easy to get sucked into the tasks and just focus on that. You should definitely be aware of what you’re doing, and to make sure that it’s not something potentially hazardous or just, well, dumb. It’s actually surprisingly easy to get carried away and forget all this- in the heat of the moment, maybe you’ll accidentally add organic material into a plastic container or perform an extraction and toss your product down the drain. One simple error can have a very large array of consequences, from a mild inconvenience to completely tanking the experiment.
The solution? You should be constantly thinking about what you’re doing, or thinking about what you’re going to do for the next steps in a procedure. You should be asking yourself “is this ok?”, and then making sure that anything preventable doesn’t occur. This may sound like a hassle, but every single step, as simple as it may seem, has the potential for error. At camp this year, one of the labs was the synthesis of some europium salt complex, and the final step was recrystallization and recovery via vacuum filtration. Sounds simple enough, right? So I took my recrystallized product from the ice bath, dumped it into the buchner funnel, and proceeded to rinse the flask it was in with some nice, room temperature water. The product dissolved in the water and was sucked right through the funnel into the flask with a bunch of junk, and that was that. Easily preventable mistake, half my product gone. So it is probably within your best interest to be very sure of what you’re doing and that it’s not something silly.
This might seem to contradict with the aspect of saving time and being quick, but this is actually how everything ties together. If you’ve done enough practice, it significantly reduces the chances of something silly from happening and, honestly, if you have experience you probably already know what you’re dealing with. So practice leads to no opportunities to be dumb, in which case you won’t have to constantly worry about making a mistake/recover from one, resulting in more saved time. And by not goofing, you’re in a good spot mentally and less likely to mess up. Having all four of these under your belt will allow you to execute labs exceptionally well, so it’s essential to get good at all of them.
Of course, it’s not really realistic to think that you can do every single lab perfectly just by following this guide or mastering everything here. Even the best of the best can make mistakes or have a bad day, so all you can really do is try your best.
So I guess I’ll start off this section with what you can do to prepare for USNCO labs prior to the actual competition. For starters, every single lab done in the history of the exams is online at this link. There are 2 labs during the exam, each worth 12.5 points for a total of 25. The lab then, in total, is 25/200 points, so only 12.5% of the total. However, lab is what differentiates between high honors and camp, so it is essential to have a semi-competent lab if you want to make camp. I would suggest going through each individual exam, read the problems, and then writing down procedures for how you would solve the problem, since this is what you’ll need to do at the exam anyway. Then, go to the answer key and compare your procedure with what’s given (for the exams that do have them, that is- the older you go, the worse the keys are). If you don’t know how to solve one of the questions, do NOT go straight for the key. Sit there and think for up to an hour, since giving up is the exact opposite of what you should be doing. Moping around and picking up an answer key is not a viable option at the actual test, so you have to condition yourself to think even if nothing comes to mind initially.
If possible, try to get some practice performing these labs. Like I said earlier, this isn’t an option for everyone, but if you do have the opportunity then you should definitely take it. The best way to prepare for USNCO is to do the labs themselves since it gives you the feel of lab- however, the bulk of the lab is being able to think rather than execute, so even if you don’t have access to a lab, simply looking through the problems and writing procedures is also very solid.
You can also get an edge by reading a lot of books, which covers the theory of a lot of stuff that shows up on labs. Reading an analytical chem book gives you a massive edge since it’ll basically tell you how every single titration in existence works, such as acid/base, iodo/iodimetric, EDTA, permanganate/dichromate/cerium/other redox titrations, and others. But overall, reading books is a massive help since if you can understand the theory behind one of the lab questions, then writing a procedure and figuring out the answer becomes simple. I recommend reading Harris and Skoog for this information.
A big second is knowing how the Olympiad works, and the patterns in labs so you can start to predict what’s to come. I’ve done a lot of analysis of the lab section of USNCO (or the more recent years really, since that’s what really matters) , and my conclusions are the following:
- 2018: EDTA Titration + Paper Chromatography - 2016: Acid Base Titration + Kinetics - 2014: Acid Base Titration + Paper Chromatography - 2012: Acid Base Titration + Kinetics
- 2019: Sodium Polyacrylate Effectiveness + Calorimetry - 2017: Alka Seltzer Composition + Qualitative Analysis - 2015: Hydrogen Peroxide Composition + Equilibrium - 2013: Really Shady Reactions Lab + Calorimetry
I’ll start with why this trend occurs and why it’ll probably continue for a while. The first is that there’s limited time to test the labs, so they can’t pair two things that would require a long time. Titrations are very long experiments, so they put something very simple that can be done quickly (kinetics) or that can be set up quickly and requires little to no management (chromatography). For the out-of-the-box labs, they’re also kind of long but require much more thinking and improv, so they pair it with something that pretty much everyone knows how to do (calorimetry, qualitative analysis) or they’ll literally tell you how to do it (that equilibrium problem from 2015), so even if you completely tank the wack lab since the thinking required is very theory based, you still have something redeemable. They also can’t repeat labs that they literally just did, so they have to alternate- it just so happens to be that they alternate every other year.
So how does one go about doing these labs? Well, for the more standard labs, you should be well experienced with how they’re performed and how to write them. For an acid base titration, the procedure should look something like so:
This sample procedure provided should tell you a few things- first, these procedures should be short. You really don’t have all that much space to write, and if it’s super messy and long then you probably won’t even want to do it; the more concise it is, the more professional and organized it appears. Keep it smart but also don’t overdo it with unnecessary details so it’s easily repeatable and not cluttered. Additionally, you should always indicate equipment used and what the graduation is, as well as how much reagent you’re using and the concentration, if provided. Indicating that you’re going to do multiple trials is also free points, but just remember to actually do them.
In each lab, they’re always going to be looking for qualitative observations. Obviously they’re not going to tell you they’re looking for this, but it’s always worth points. For titrations, it’ll be things such as color changes. For calorimetry, it could be simple observations (bubbling, fizzing, color changes)- you just have to remember to write them down. There should pretty much always be some way you can get some qualitative data down, and you should always write down your observations.
A lot of questions I get are how you go about solving the really wack, never before seen labs. Luckily, for this upcoming year you probably won’t have to deal with that, but I’ll still explain how to approach them. First, tap into your theory knowledge, since if there’s ever a lab that requires theory, it’ll be this one. For the polyacrylate, it was knowing that it was about knowing what it does, as well as osmosis/cation binding. For the alka seltzer lab, it was about limiting reagent stoichiometry as well as acid base reactions. So definitely spend more time thinking about how to do these labs, since they’re very theory based. Furthermore, everything that’s given to you has a purpose. They won’t give you something random for absolutely no reason- try to think why it’s given and what role it can play. My first year was 2017, and when I had the alka seltzer lab, I knew what to do with the excess acid provided but had absolutely no clue why they gave extra sodium bicarbonate. Coincidentally, I couldn’t get the mass percent of citric acid in the tablet; I wonder why that is? So keep in mind what’s provided and how you can use it, since if you’re not using a provided reagent for one of these labs you’re probably missing something.
Once you’ve finally collected some data, you should set up another trial and start making calculations. The points don’t come from finishing the lab, but having presentable data and completing the actual questions. The worst thing that could ever happen is having all the data, then getting time locked and not being able to answer any of the analysis questions. It’s a good idea to have those done somewhere in between your first and second trial for each lab, so you at least have something written down. Your second trial will either support your conclusions, which is good, or it’ll refute it. If that’s the case, run a third trial and even maybe a fourth trial if you really want, then adjust your calculations and change answers if necessary. But this knocks out the two most important parts of the lab- analysis and sufficient data. Also, if you get really lucky, you can answer some analysis questions without even doing the lab. 2019 had 2 of these questions (what is the role of the ferric ion, how does sodium polyacrylate work), which is why you should always read the analysis questions before starting to see if you can get anything written down early.
Finally, cleanup. Don’t get snobby about this- since they can and will dock points if you don’t clean up well. Wash everything twice and wipe it down with a paper towel, then organize everything so it looks presentable. Wipe down the lab bench and throw away any junk that you might have used- paper towels, pH paper, etc. Just do the cleanup normally and you’re done!
Editor's note: his prediction is wrong because it never happened
I’d like to think that I’m getting pretty good at this, since I was able to guess calorimetry for 2019, and EDTA titration and chromatography for 2018. So without further ado, here are my predictions:
I am 100% certain that there’s going to be a titration this year, since ACS loves titrations and because it wasn’t tested last year. ACS has also moved beyond acid base titrations, and will probably start looking for more analytically experienced chemists. They will definitely not whip out another EDTA lab since they just did it and they’re easy, and probably not acid base since they’re also rather simple. My first prediction is some iodine titration, since the iodine + thiosulfate titration is very famous and has good analysis that requires knowing redox reactions and good stoichiometry. They won’t give permanganate or dichromate since not only are they expensive, but they’re just so damn messy, hard to dispose of, and toxic. So iodine and thiosulfate are the safe ways to go.
For the second lab, it’s something that’ll be so simple and generic that knowing exactly what it is probably won’t really help. I’m leaning toward a kinetics lab just based off of what the trends have been, probably with reaction order determination and possibly catalytic efficiency. However, given that USNCO has been getting more difficult, I can also see them throwing in qualitative analysis-since it hasn’t been done in a while- with a twist, such as providing NaF, AgNO3, and CaCl2 and knowing that CaF2 will precipitate and AgF will not. However, this one is a bit more open since it’s a designated “easy” lab and I am 100% certain as to what will show up. I can say that it will definitely be a simple, straightforward lab. I’m around 95% sure that it’ll be one of the two that I predicted, though.
Predictions are predictions though, so if it’s not what I have written down then oh well.
So at the international level, you’re not writing procedures, but rather following one. You’re given 3 labs to complete in 5 hours, which sounds easy until you realize that the labs are super long and each difficult to do in its own way. One lab will always be an organic synthesis/scheme/reaction, and another will be a titration of some sorts. The third will be some oddball of sorts, typically with thermodynamics or kinetics.
The best way to start preparing for this level of lab is to have a very good understanding of what’s on the prep. The preparatory problems are provided online from that official IChO website, and the actual labs will be somewhat based off of them. A lot of the techniques that are tested within the prep have a very high chance of showing up on the actual exam, so at the very least you should at least read through the preparatory problems and know how to do them. When it comes to camp, they will literally print out the prep, slap some more analysis questions on, and give it to you to do. By reading the prep prior, you’ll at least know what you’re getting yourself into.
Practicing these labs on your own at home is a completely different story from USNCO. They’re longer, typically more hazardous, and the chemicals are nearly impossible to buy. It’s also a lot more demanding, since you’re going to need equipment such as burets, round bottom flasks, condensers, buchners, and a lot of other things that are not found within the typical household. If you’re willing to pour a ton of money into it, then by all means, you should. Getting practice for a lot of the techniques on the usefulness/difficulty tier lists will give you a massive edge over others and gives a really good feel of the lab. It should also be in your best interest to get some help from your school, since they’re probably more well equipped for this kind of thing. The only downside is that you can’t practice whenever you want, but that doesn’t actually matter since as long as you’re getting the experience it should be fine. If all else fails, like I said, you can practice the techniques using solely water and glass. I also have a list of some techniques and how to perform them well below.
If you’re going to IChO, you are going to need to practice the full labs, no exceptions. If you’ve made it that far, you’re probably already really good at lab, and camp just gave you a lot more time to practice. But I’d still recommend giving the practical preparatory problems another whirl at least once before you head off.
These labs are all about managing your time well and multitasking. From the moment you get your packet to the moment you turn it in, every second counts. So the first thing you should do is read the labs that you’re given very, very carefully. Pay close attention to the time you have to wait for certain steps, and use that to start weaving a framework for what your plan will be. You should definitely be alternating between labs, performing one step and then moving to a different step in a completely different lab. When waiting for one step to finish (usually the organic stuff), you should be planning to work on the other labs and potential analysis questions that you can actually answer. Through lots of practice, you’ll have a very good gauge on time- for example, 10 minutes is enough time to make stock solutions or run a titration and set up another one. It’s essential that you know what you can and cannot do within a given time period so that you can maximize efficiency and not get killed by time crunches. By the time you’ve finished reading your lab packet, you should have a good understanding of what your plan is. I would say that if there are a lot of steps or if you don’t have as much lab experience, you only need to really know what you’re going to do for the first half an hour or so, then continue thinking about your plan throughout the entire lab time, since mapping out the entire thing is very difficult and sometimes isn’t feasible. However, it’s crucial to weave the labs into one another and perform them together rather than one at a time. The labs are set up so that you literally can’t do this and finish on time with good data.
If I were to give a very generic outline, it would look something like this:
However, this is the most generic plan you’ll ever see and should not be followed completely, since it’s just too general. However, the important features are that you should always start with the longest lab (usually organic), with your plan for labs 2 and 3 revolving around it. You should also be setting up equipment at the very beginning while waiting, such as creating the TLC chamber and preparing for filtration. After recrystallization, it shifts to labs 2 and 3 being the priority, while doing the organic lab when you have time. This is due to the fact that typically all that’s left is TLC and melting point, which you weave into your plan for the remaining labs. Finally, analysis questions should be scattered throughout so you don’t have to do them all at once at the very end and risk a time lock. You also should be turning in organic product and TLC early.
It should also be kept in mind that the plan you create is going off of the basis that everything happens ideally. Hopefully it runs as planned, but in the case of an emergency you simply have to backtrack and make up for all the lost progress. This, however, does not mean you drop everything else. You should still be weaving in parts of other labs as you recover, which is hard to remember since you’ll probably be internally panicking if you make a mistake. But as stated above, keep a cool mental game and calmly readjust your plan- in the long run, it should look pretty much the same near the end- only what you do immediately is really affected.