Chemistry Olympiad Exams

Having the right tools to prepare for the local, national and international olympiad exams is the key to success at each level. Take practice exams, attend webinars and get even more help by participating in our support programs.  

Exam Preparation Opportunities 

Visit the USNCO Support Programs page to watch the recordings of the USNCO webinars, access the USNCO Preparation Hub to use and share resources with fellow students. 

Exam Organization

Multiple choice USNCO (both local and national) exams cover the following topics:

 1 – 6  Stoichiometry/Solutions
 7 – 12  Descriptive/Laboratory
 13 – 18  States of Matter
 19 – 24  Thermodynamics
 25 – 30  Kinetics
 31 – 36  Equilibrium
 37 – 42  Oxidation - Reduction
 43 – 48  Atomic Structure/Periodicity
 49 – 54  Bonding/Molecular Structure
 55 – 60  Organic/Biochemistry

Local Chemistry Olympiad Exams

Nearly 16,000 U.S. students participate in Local Chemistry Olympiad competitions. Over 70% of Local Sections use the Local Section Exam prepared by the ACS Chemistry Olympiad Examination Task Force. Exams are administered annually in March and students are nominated for the U.S. National Chemistry Olympiad competition based on their performance and eligibility.

National Chemistry Olympiad Exams

The U.S. National Chemistry Olympiad National Exam is a 3-part, 4 hour and 45 minute exam administered in mid or late April by ACS Local Sections and International Chapters. Roughly 1,000 students participate in this exam each year. Students must be nominated by their coordinator to participate, and only a limited number of nominees are accepted per Local Section or International Chemical Sciences Chapter. Eligibility rules apply.

Part I Part II Part III
  • Multiple Choice
  • 90-minutes
  • 60 multiple choice questions
  • Covers broad chemistry topics
  • Problem Solving
  • 105 minutes
  • 8 written questions
  • Covers chemical theories and models
  • Lab Practical
  • 90 minutes
  • 2 laboratory practicals
  • Involves problem solving in the laboratory

Past Local Chemistry Olympiad Exams

Past National Chemistry Olympiad Exams

Volunteer to Annotate Exam Solutions

Volunteers are coordinating efforts to annotate past USNCO exams to further help students prepare. This project is covering the Local Section Exam and Part 1 of the National Exam (detailed solutions are provided directly in the files for National Exam Parts 2 and 3). Links to annotated files are included next to the corresponding exam below. High school students, teachers, and other USNCO volunteers are invited to assist in this project.

This project is being coordinated by Dr. Qiang "Steven" Chen.  If you would like to assist in annotating exams, please contact

To suggest corrections to past solutions, please submit them in the USNCO Preparation Hub.


Exams Task Force Members

  • Chair: Seth N. Brown, University of Notre Dame, Notre Dame, IN
  • James Ayers, Colorado Mesa University, Grand Junction, CO
  • Jerry Bell, Simmons University, Boston, MA (retired)
  • Mark DeCamp, University of Michigan, Dearborn, MI (retired)
  • Joshua de Groot, College of Southern Idaho, Twin Falls, ID
  • James Dohm, Vanderbilt University, Nashville, TN
  • Xu Duan, Holton-Arms School, Bethesda, MD
  • Valerie Ferguson, Moore HS, Moore, OK
  • Julie Furstenau, Thomas B. Doherty HS, Colorado Springs, CO (retired)
  • Kimberly Gardner, United States Air Force Academy, CO
  • Paul Groves, South Pasadena HS, South Pasadena, CA
  • Nicolas Hamel, Clackamas Community College, Oregon City, OR
  • David W. Hostage, Taft School, Watertown, CT
  • John Kotz, State University of New York, Oneonta, NY (retired)
  • Michael A. Morgan, Francisco Bravo Medical Magnet HS, Los Angeles, CA
  • Jane Nagurney, Scranton Preparatory School, Scranton, PA (retired)

Laboratory Task Force Members

  • Chair: Kelli Slunt, University of Mary Washington, Fredericksburg, VA
  • Payton Bailey, University of Mary Washington, Fredericksburg, VA
  • Jesse Bernstein, Miami Country Day School, Miami FL (retired)
  • Alexsandra DaSilva, SUNY, Binghamton, NY
  • Myra Halpin, NC School of Science & Mathematics, Durham, NC (retired)
  • Nicolas Hamel, Clackamas Community College, Oregon City, OR
  • Innocent Pumure, University of Central Missouri, Warrensburg, MO
  • Lawrence Wilkinson, ExxonMobil, Baton Rouge, LA

Exams Annotations Volunteers

  • Editor: Qiang "Steven" Chen, Princeton International School of Mathematics and Science, Princeton, NJ
  • Annapurna Canumalla, Eastside Tutoring Academy, Sammamish, WA. National Exam 2018.
  • Harys Dalvi, American Heritage School Boca Delray, Boca Raton, FL. Local Section Exams, 2016 - 2020.
  • Andrew Ni, Amherst College, Amherst, MA. National Exam, 2017.
  • Aaron Oong, Methodist College Kuala Lumpur, Kuala Lumpur, Malaysia. National Exams, 2017-2019
  • Ron Shprints, Makif Gimmel High School, Ashdod, Israel. National  Exams 2016, 2018
  • Ritvik Teegavarapu, American Heritage School Boca Delray, Boca Raton, FL. Local Section Exams, 2016 - 2020.
  • Aditya Udgaonkar, BASIS Independent Silicon Valley, San Jose, CA. National Exam, 2016.
  • William Wu, Princeton International School of Mathematics and Science, Princeton, NJ. National Exams, 2016-2018
  • Jason Zhang, The Carol Martin Gatton Academy of Mathematics and Sciences, Bowling Green, KY. National Exam, 2016
  • Alec Zhu, Lexington High School, Lexington, MA. National Exams, 2017-2020