Prepare for Exams
Students interested in competing must register with ACS by completing the registration form no later than December 15, 2023. Registration does not guarantee participation in the program.
Having the right tools to prepare for Local, National and International Olympiad Exams is the key to success at each level. To prepare for exams, explore our resources below to:
- Review past exams for practice
- Take advantage of our recorded webinars
- Network and collaborate

More Resources
- Get help from our webinars
- Learn how many nominees are allowed from Local Competitions and how National Exam scoring works
- Use Accessible Periodic Table
- Use Exams Reference Page
Review Past Exams
Links to annotated files are included next to the corresponding exam below. Detailed solutions are provided directly in the files for National Exam Parts 2 and 3.

Local Chemistry Olympiad Exams

National Chemistry Olympiad Exams
Detailed solutions are provided directly in the files for National Exam Parts 2 and 3.
To suggest corrections to past solutions, please submit them in the USNCO Preparation Hub.
Solutions are kindly annotated by our volunteers, view all acknowledgments. Sign up as a volunteer to annotate past exams.
USNCO Preparation Hub
Communicate With Fellow Students
This forum is open to anyone interested in USNCO. Share your favorite resources, ask questions of our volunteers, or share comments/suggestions for annotated solution guides in the relevant forums. You only need an ACS ID to login and join the conversation (a member number is not required).
Encouraging environment
Free and easy registration
Meet with people like you


USNCO Coaching
Get extra help with a USNCO Coach
USNCO Coaching program will be continued in 2024. Applications from high school chemistry teachers are now accepted. The deadline for teachers to submit an appliction to serve as a USNCO Coach is October 23, 2023.
Student registraion is open, application deadlinefor students is December 18, 2023.
Get extra help during 2-hour sessions for small groups, led by coaches from across the U.S. Coaching sessions will be organized over Zoom and coordinated by the American Chemical Society.
Professional coaching
Easy access over Zoom
Small group study sessions