The International Chemistry Olympiad (IChO) is an international competition organized for pupils of the secondary schools that are not specialized in chemistry. From the very beginning there were discussions about the content of the competition tasks since it was supposed there might be problems between the content of the competition tasks and different study programs for teaching of chemistry in the schools of participating countries. When the number of participating countries is small the problem can be solved a the content of the tasks can be adapted to the level of the countries. The problem becomes acute when the number of countries is greater. Therefore, it was clear very soon that any system is necessary which would give information to the students but also to their teachers about the level and fields of chemistry applied in the next competition problems.
Already seven countries participated in the IChO in the year 1972. The organizers of the IChO tried to solve the problem by preparing of 60 preparatory problems (in Russian language and without solutions). It was a first attempt and the preparatory problems became a part of the organizers’ duties from the year 1976.
It is stated in paragraph 10 of the present accepted regulations of the International Chemistry Olympiad that:
“The organizer distributes a set of preparatory tasks written in English to all participating countries in January of the competition year. The preparatory tasks are intended to give students a good idea of the type and difficulty of the competition tasks, including safety aspects. SI units should be used throughout the preparatory tasks.
The total number of theoretical and experimental tasks in the set of preparatory problems cannot be lower than 25 and 5, respectively.”
Many preparatory problems are archived in the IChO International Information Centre in Bratislava. A complete series of the tasks (problems and their solutions) from the years 2001 - 2019 were edited by A. Sirota, director of the Center.
This review of the preparatory problems should serve to both competitors and their teachers as a source of further ideas in their preparation for the IChO competitions. For those who took part in some of these International Chemistry Olympiads the collection of the problems could be of help as a study, archival and documentary material.