Brazilian Chemistry Olympiad¶
Olimpíada Brasileira de Química
Key Websites¶
Overview¶
The Olimpíada Brasileira de Química (OBQ, Brazilian Chemistry Association) is Brazil's national chemistry competition for secondary-school students, promoted by the Associação Brasileira de Química (ABQ) and coordinated by the Universidade Federal do Ceará (UFC, Federal University of Ceará) and the Universidade Federal do Piauí (UFPI, Federal University of Piauí). It covers all 27 Brazilian states and has accumulated approximately 500,000 participants across all levels since its founding.
Programme Family
The OBQ is part of a broader olympiad ecosystem:
- OBQJr (Junior): For students in grades 6–9 (ages ~11–15), entirely online
- Quimeninas: National female-only chemistry olympiad, promoting gender equity in STEM
- OBSQ: University-level chemistry olympiad for undergraduates
Competition Format¶
The OBQ uses a multi-stage pyramid structure with two modalities.
-
State Olympiads (Phases I–II)
- Each of the 27 states runs its own chemistry olympiad as the qualifying gateway
- Typically held in June–August (registration April–May)
- Over 50,000 students participate in state-level events in recent editions
- Each state may advance up to 140 students to the national phase (80 in Mod A, 60 in Mod B)
-
National Phase (Phases III–VI)
- Phase III (August): National theoretical examination; medals and honorable mentions awarded
- Phase IV (September–October): Laboratory-knowledge evaluation via video experiments (Mod A medalists only)
- Phase V (November): Advanced chemistry course for the top ~15 performers
- Phase VI (following year, April–May): Final theoretical evaluation to select national teams
-
International Representation
- Top 4 scorers represent Brazil at the IChO
- Ranks 5–8 represent Brazil at the Ibero-American Chemistry Olympiad (OIAQ)
- Variable number from top 20 represent Brazil at the Mendeleev International Chemistry Olympiad (IMChO)
Modality A vs Modality B¶
The OBQ splits students into two modalities based on grade level to ensure fair competition:
| Feature | Modality A | Modality B |
|---|---|---|
| Grade levels | Grade 9-11 | Grade 12 |
| Approximate ages | ~14–16 years old | ~17–18 years old |
| State quota | Up to 80 students per state | Up to 60 students per state |
| Phase IV (lab) | Yes — lab evaluation via experiment videos for medalists | No |
Why two modalities?
Third-year students have completed the full high school chemistry curriculum, while 1st–2nd year students are still building foundations. Separating them ensures fair competition. Modality A also includes a practical laboratory component (Phase IV) that provides younger students with hands-on experience.
Student Outcomes¶
OBQ medalists can gain direct admission to major Brazilian universities through vagas olímpicas (olympic spots), bypassing the traditional entrance examination (vestibular/ENEM):
| University | Quota |
|---|---|
| USP (Universidade de São Paulo) | Typically offers 230+ olympic spots across 100+ courses |
| Unicamp (Universidade Estadual de Campinas) | Allocates ~130 olympic spots |
| Unesp (Universidade Estadual Paulista) | Offers ~450 olympic spots |
Combined, the three major São Paulo state universities offered over 800 olympic admission spots in recent cycles.
History¶
- 1986: The OBQ was founded through an initiative of the Chemistry Institute at the Universidade de São Paulo (USP), initially involving five states. This early version of the competition was short-lived.
- 1989–1995: The competition was suspended for approximately seven years due to organizational challenges.
- 1996: Revived by UFC (Universidade Federal do Ceará) and UFPI (Universidade Federal do Piauí), establishing the coordination model that continues today.
- 1999: Brazil made its IChO debut at the 31st IChO in Bangkok, Thailand.
- 2008: The OBQJr (Junior) programme was established, targeting students in grades 6–9 with an entirely online format.
- ~2022: Quimeninas (National Female Chemistry Olympiad) was launched, promoting gender equity in STEM. Female participation in OBQ expanded from 35% to 52% following targeted programs including Quimeninas.
OIAQ Hosting Record¶
Brazil has hosted the Olimpíada Iberoamericana de Química (OIAQ) 6 times, more than any other nation:
| Year | Location | Edition |
|---|---|---|
| 1997 | Rio de Janeiro | 2nd OIAQ |
| 2007 | Rio de Janeiro | 12th OIAQ |
| 2011 | Teresina | 16th OIAQ |
| 2015 | Teresina | 20th OIAQ |
| 2021 | Teresina (online) | 25th OIAQ |
| 2026 | Fortaleza | 30th OIAQ (jubilee) |
Brazil is described as "the historically dominant nation" in OIAQ.
Mendeleev Olympiad Hosting (2025)¶
May 2025: Brazil hosted the 59th Mendeleev International Chemistry Olympiad (IMChO) in Belo Horizonte, organized by the Melnichenko Foundation and the chemistry faculty of Lomonosov Moscow State University, with the local partner being the Federal University of Minas Gerais (UFMG). 40 countries participated, making it one of the largest IMChO editions ever.
Brazil's well-developed olympiad infrastructure (UFC, UFPI, ABQ network) and prior experience hosting international chemistry events (6 OIAQ editions) made it a natural choice as host.
IChO Performance¶
IChO Medal Record
3 Gold · 
23 Silver · 
54 Bronze · 
7 Honorable Mentions
OBQJr and Quimeninas¶
OBQJr (Junior Olympiad)¶
The Olimpíada Brasileira de Química Junior targets students in grades 6–9 (ages ~11–15), with no age limit — only grade level matters.
| Feature | Details |
|---|---|
| Modalities | Mod A: 6th–7th graders; Mod B: 8th–9th graders; Mod C: adapted test for students with medical documentation |
| Format | Entirely online. Phase I: 20 objective questions (2 hours); Phase II: 10 objective + 4 analytical questions (top 50 per modality per school) |
| Founded | ~2008 (exam archives date back to this year) |
| Awards | Top 90 nationally receive gold medals |
| Impact | Since creation, 68 OBQJr students have gone on to represent Brazil internationally |
Quimeninas (Female Olympiad)¶
The Olimpíada Nacional Feminina de Química is exclusively for female students in Brazil, from 9th grade through high school.
| Feature | Details |
|---|---|
| Format | Single-phase, entirely online, free. 18 multiple-choice + 3 analytical-expository questions |
| Awards | 996 medals distributed across national, state, and demographic categories |
| Founded | ~2022–2023 |
| Purpose | Increase female representation in STEM, reduce gender disparities, identify talented students |
| Impact | Female participation in OBQ expanded from 35% to 52% following targeted programs |
| Example | In Alagoas alone, 2,095 young women participated in 2025 |
Quimeninas is part of the broader Movimento Meninas Olímpicas movement for gender equity in Brazilian science olympiads.