United States National Chemistry Olympiad
The United States National Chemistry Olympiad (or USNCO) is a contest held by the American Chemical Society (ACS) used to select the four-student team that represents the United States at the International Chemistry Olympiad (IChO).
Each local ACS section selects, in whatever way it chooses, eight students (or more for larger ACS sections) to take the USNCO National Exam. One way to select these students is with the USNCO Local Exam, which is a significantly easier version of the National Exam consisting of 60 multiple choice questions. Thus, the first step on the path to the USA IChO team is usually the local exam.
Exam format
The National Exam consists of three parts.
Multiple choice
The first part contains 60 multiple-choice questions. Each question has four answer choices. There is no penalty for guessing; a student's score is equal to the number of questions answered correctly. One and a half hours (90 minutes) are allotted for this first part.
Free response
The second part contains 8 free response questions. Complete written explanations and calculations are required for full credit on a question. Partial credit is awarded.
Lab practical
Beginning in 1994, the lab practical was added to the National Exam. It contains two tasks to be performed by each student with only the specified materials. Past tasks have included chromatography, titration and qualitative analysis.
Limitations to participation
USA representation limits
As the USNCO is seen as a process in which potential candidates for the USA IChO team, only United States passport-holding residents may proceed to the training camp from the USNCO. Further, those who are deemed not fit to represent the United Stated for discipline reasons during the training camp may be barred from selection for the IChO team, although such cases are extremely rare.
Special limitations
The purpose of this section is to explain some of the special participation limitations that seem otherwise unjustified.
The USNCO and the entire process of the USA IChO team selection is coordinated by the education division of the ACS, also known as DivChEd. As an educational organization, the use of the USNCO and the IChO as an chemistry awareness and education process is paramount. Doing well at the IChO, although desirable, is not as nearly as important for DivChEd. Therefore, a maximum of two students from the same educational institution are allowed to participate in the USNCO, even if more students qualify for the USNCO in a local section based on score. This rule prevents a science-oriented school from sending excessive numbers of people to the training camp, and thus limiting the USNCO's impact on chemistry awareness across the United States. Also, the efficiacy of the chemistry training camp may be decreased if it is overwhelmed by students from one school, which would result in a worse USA IChO team.
One other special limitation is that a person who has earned either a gold or silver medal in the IChO may not participate again in the study camp. This limitation is put in place purely for the chemistry awareness, as a student who has learned from one year's IChO most likely will do much better in the following year. The rationale for not limiting a person who has been awarded honorable mention or a bronze medal from competing the following year is likely based on the fact that if the USA team was in a condition that there were bronze medalists or lower, then the chemistry awareness may be sacrificed for the performance of the team.
Note that the only official reason that ACS gives for these limitations is "chemistry awareness", and that more detailed explanations are purely speculative, but they seem much more reasonable than any other possible explainations with the information given.
USNCO Study Camp
The top 20 scorers on the USNCO National Exam are invited to participate in the two-week USNCO Study Camp at the United States Air Force Academy in Colorado Springs, Colorado. At the camp, the students are tested (both free response and lab testing), and the top four students are selected to comprise the U.S. IChO team. Two alternates are also selected, although no alternate has ever actually been called up for duty.
Scope of the test as compared to the IChO
The purpose of the USNCO is to select those students who have the chemistry skills necessary to compete in IChOs in general as determined by past IChO. In contrast, the testing administered at the actual training camp aims to select those students who have the skills do to well on the topics that will be covered in the immediate upcoming IChO. Since the host country each year may design the test to their preference, the scope of the USNCO and the training camp may be widely different.