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How to Prepare for the U.S. National Chemistry Olympiad (USNCO)

If you want to develop and highlight your skills in chemistry, preparing for the U.S. National Chemistry Olympiad can be a great way to showcase your passions.

If you’d like to know how to participate, this guide will show you how to do well in this competition.


What is USNCO?

The U.S. National Chemistry Olympiad, sponsored by the American Chemical Society, is a multi-tiered competition designed to promote achievement in high school chemistry.


Local Chemistry Olympiad competitions are open to all U.S. high schoolers in the United States each March. Top performers at the local level are invited to compete in the National Chemistry Olympiad Exam, after which the top 20 highest-scoring students from the National Exam spend two weeks at a Study Camp to undergo rigorous training.


At any level of USNCO, the goal is to support young people in achieving excellence in chemistry and recognize outstanding chemistry students. Topics found within test content typically include descriptive chemistry and laboratory techniques, stoichiometry, states of matter, thermodynamics, kinetics, equilibrium, electrochemistry, electronic structure and periodic trends, bonding theories, and organic chemistry.



Who is eligible to participate in USNCO?

  1. Students must be U.S. citizens or legal, permanent residents of the United States (green card holders).

  2. High school students enrolled in 9-12th grade who will graduate no earlier than the first of May of the year.

  3. Students must be under 20 years of age on the first of July of the year of the competition.

  4. No more than two students per high school per local section may be nominated to take the National Exam.

  5. Eligible students who have previously attended the study camp automatically qualify for

  6. Winners of gold medals at the International Chemistry Olympiad are not eligible.

  7. A student may participate only in the competition of the section in which the student's high school is located. In the case of a cyber-student, the student shall participate in the local section where he or she is geographically located.

  8. A student who participates in the Physics Olympiad study camp, the Mathematics Olympiad study camp, or the Biology Olympiad study camp is not eligible to participate in the Chemistry Olympiad study camp during the same summer.

What is the International Chemistry Olympiad (IChO)?


Based on their performance at Study Camp, four students are chosen to represent the U.S. in the International Chemistry Olympiad (IChO), which takes place in July.


How do you participate in USNCO?

Participation in the USNCO starts with taking part in local competitions held in March. Students interested in competing must work with their high school chemistry teacher who registers the school to participate in the program. If their school does not participate in the competition, then the student’s parent or guardian can contact the USNCO Coordinator at their ACS Local Section.

What is the timeline?


The timeline of USNCO may be subject to change, but the general timing of events looks like this:

Local Exam: March 1-31

National Exam: April 15-23

Study Camp: June 4-17

International Chemistry Olympiad: July 16-25


How to study for USNCO at the local level?


A good prerequisite to prepare for USNCO is to have a solid basis in algebra and attended classes in Honors Chemistry or equivalent.

One of the best ways to prepare for the competition is to take and review past tests, which are available online. USNCO is known for having similar questions across multiple exams, sometimes even having the same question between two separate years. Not only does this allow you to test your knowledge in chemistry, but it also helps in familiarizing you with the format of the exam.

For the local competitions, students are expected to tackle 60 questions within the span of 110 minutes. Students do not need to answer all questions in order to qualify for the next round.


When does the USNCO honors list come out?


Information about the dates is not readily available. Because cut-off scores vary by year and region, it is recommended that you find this information by emailing the Local Coordinator or checking the High Honors/Honors list in the past 2-3 years to see the performance of your high school and Local Section in the National Exam. If the region has several students in the High Honors/Honors list each year from different schools, it means that your region may be relatively competitive with a higher cutoff. The USNCO 2022 results can be found here.


While past exams are useful, there are many free resources available as well. For example, CODS is a student-run organization committed to helping people study; previous Study Camp and IChO participants write Mock Exams of all levels, and they host informal mock tournaments. Anugrah, a past IChO gold medalist and mentor at the 2021 Study Camp, also hosts a website to accommodate different study resources.


Some books that are known to be helpful are AP Chemistry books, Chemical Principles by Atkins or Chemical Principles by Zumdahl, and Klein Organic Chemistry.


What about the national level?


The format of the national level test is different from the local competitions. The test is divided into three parts:

  • Part I is the multiple-choice, 90-min, 60-question test. It is faster-paced and more difficult than the local competition exams.

  • Part II is the free-response, 105-min, 8-question section that tests more advanced chemistry knowledge that expands beyond AP Chem knowledge.

  • Part III is the lab practical, 90-min, 2 problems section. Rather than answering questions on paper, students will be given the necessary chemicals by the proctor and solve the question hands-on.

While the structure of the exam is different, the same resources as above can apply to studying for this exam. Past exams and free resources by past USNCO participants are available. However, the interval of time between the local competitions and national exams is short, so you should not expect to get much studying done during this time frame. It is recommended to study this content before the local exams, and if qualifying for the national exam, review the questions after.


If you are interested in exploring other chemistry competitions, check out our list of great competitions here.


Want extra support? The Lumiere Research Scholar Program

If you’re looking for a mentor to participate in a science competition like USNCO or want to build your independent research paper, then consider applying to the Lumiere Research Scholar Program. Last year over 2100 students applied for about 500 spots in the program. You can find the application form here.


Lydia is currently a sophomore at Harvard University, studying Molecular and Cellular Biology. During high school, she pursued engineering activities like attending the Governor's School of Engineering and Technology. In her spare time, she likes to create digital art while listening to music.

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