ICO Part B (ORI)

ORI is the label used for the practical (laboratory) examination, Part B of the competition. You work at a bench on an assigned experimental task and submit a written answer sheet. It is distinct from the theoretical paper, and it is set and marked by the host country, so its content differs every year.

The duration is set by the host country for that year's competition and is stated in the official regulations and the practical paper itself. It is not fixed across editions, so check the current host's published programme rather than relying on what earlier competitors report.

Medal boundaries are decided each year from the combined theoretical and practical results, so no fixed number exists. The official IChO regulations and the host's results documents describe how awards are determined. Aim to maximise both accuracy and the quality of your written reasoning rather than chasing a target score.

No. The IChO is an annual competition with national selection, and a candidate represents their country once in a given year. If you are still eligible by age and enrolment, you can try to qualify again through your national olympiad in a later year; eligibility rules are published by the organisers.

They test different things. The theory paper rewards breadth and speed of problem-solving; the practical rewards careful hands, planning, and honest data treatment. Many strong theorists lose marks through poor technique or sloppy significant figures, so treat the laboratory as a separate skill to train, not an afterthought.

First, master the fundamentals: accurate weighing, volumetric glassware, titration technique, recrystallisation and melting-point measurement. Then practise complete unfamiliar procedures end to end under time limits. Finally, drill report writing - tables, graphs, error propagation and short explanations - because those marks are the easiest to secure and the easiest to lose.

Contamination from dirty glassware, overrunning the time limit on one step, recording raw data on scraps instead of in the answer sheet, quoting too many or too few significant figures, and giving no comment when a result deviates from the expected value. Reading the whole procedure before starting prevents most of these.

You need to know the topics listed in the official IChO syllabus, but the practical paper tests application, not recall. Know how to calculate concentrations, propagate uncertainties, plot and interpret a calibration or kinetic curve, and identify a compound from given spectra. The official syllabus is published by the IChO organisers.

Past practical papers, preparatory problems and regulations are published on the official IChO website and on the sites of individual host countries. Those are the authoritative sources for the current year's format, timing and rules; use them rather than unofficial summaries.

No. This is independent study material written for candidates preparing for the practical examination. It is not produced, endorsed or reviewed by the International Chemistry Olympiad or any host country, and it should be used alongside the official syllabus, regulations and past papers.