The HMChO is an international chemistry competition founded by students from Harvard and MIT, aiming to challenge and inspire high school students to go beyond chemistry school curriculum by providing a rigorous assessment modeled after the U.S. National Chemistry Olympiad.

Any high school student (equivalents of U.S. grades 9-12) worldwide (though the competition is designed mostly for U.S. students, international students are welcome to register as well) can register (all students participate in the same division). 

The exam will be held on March 8, 2025.  

No, the 2025 competition will be conducted entirely online. However, we are working on having future competitions transition to an in-person format.

The competition consists of two parts:  

- Part I: 60 multiple-choice questions (90 minutes);  

- Part II: 8 written-response problems (105 minutes, additional 15 minutes for file scanning and upload);  

- Break: 30 minutes between Part I and Part II. 

The exam is conducted online via Gradescope, with live proctoring through Zoom.  Students will receive a Zoom link and an invitation to join HMChO 2025 on Gradescope before the competition. For more details about exam security and regulations, see the Information page.

Students must join their assigned Zoom session 15 minutes before the exam. Proctors will conduct an identity verification check in a one-person breakout room before allowing students to enter a larger ten-person breakout room.

Students must position their webcam at an angled side view, ensuring their workspace (table and writing surface) and part of their upper body (hands and head) are visible throughout the exam.  For more examples of proper and improper setups, see the Information page.

Students may not leave their rooms during the 90-minute and 105-minute examination periods. However, they may take a break during the 30-minute intermission between Part I and Part II. 

We are only offering accommodations such as permission for a medical device on the desk (e.g, glucose monitors) and permission for more bathroom breaks due to medical reasons (e.g, kidney problems), so after you complete the registration form, we will reach out to see if we can work this out for you.

There will be a practice test available on Gradescope before the competition, which we strongly recommend students try out in order to familiarize themselves with the platform and submission process. 

The total score is calculated as: Total Score = (1.25 × Part I Score) + Part II Score, where Part I is 60 multiple choice questions worth 60 points in total and Part II is 8 free written-response questions worth 100 points total.

If students receive the same score, tiebreakers are applied in this order:  

1. Higher Part II Score;  

2. More correct answers on difficult Part II problems;  

3. More correct answers on difficult Part I questions. 

Appeals will not be accepted unless there is a clear error in the answer key. In such cases, students must submit an appeal to hmcho.inquiries@gmail.com within 24 hours of the answer key being published. 

Participants will receive certificates as follows:

- Top 10 Students - For the top 10 students;

- High Honors – For the top ~5% of students; 

- Honors – For the next 10% of students (for the top ~15% of students overall).