What It Is
The U.S. National Chemistry Olympiad and the International Chemistry Olympiad are multi-tiered competitions that bring together the world’s most talented high school students to test their knowledge and skills in chemistry. Nations from around the world conduct examinations to choose the most high-performing students to represent their countries in the International Chemistry Olympiad.
U.S. National Chemistry Olympiad
Each year more than 10,000 high school students nationwide take local exams hoping to compete in the U.S. National Chemistry Olympiad. The top 20 students from the national exam participate at a study camp, held each June at the U.S. Air Force Academy in Colorado, and four are chosen for the U.S. team to compete in the International Chemistry Olympiad.
Taken from the American Chemistry Society's website:Chemisty Olympiad
The Chemistry Olympiad has three rounds:
100 multiple choice questions. To move to the next round, you need to be in the top 25 overall to move on. Generally, this requires a score above a 55.
Examples of local tests can be found at: Local Chem Olympiad Examples
The American Chemical Society states that,
The U.S. National Chemistry Olympiad national exam is a three-part, 4 1/2 hour exam administered in late April by ACS local sections. Nearly 900 students participate in the competition each year.
Examples of past National Exams can be found at:
National Chem Olympiad Examples
International Chemistry Olympiad
The International Chemistry Olympiad is a 10-day competition to challenge the chemical knowledge and skills of students around the world. The event, which began in 1968 in Eastern Europe, now includes participants from more than 60 countries. Each nation sends a team of four students who complete a five-hour laboratory practical and a five-hour theoretical examination.
Taken from the American Chemistry Society's website:Chemisty Olympiad Overview
A bunch of old tests: http://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_SUPERARTICLE&node_id=1508&use_sec=false&sec_url_var=region1