ACS Organic Chemistry Exam 2026: 70 Questions in 110 Minutes
November 2, 2026 · Alex S. · reviewed by Hana N., Quality Reviewer · how we write
The full-year ACS Organic Chemistry exam (OR23) has 70 multiple-choice questions and a 110-minute limit. ACS publishes national norms instead of a pass mark, so ask your instructor how the score counts.
The full-year ACS Organic Chemistry exam, the 2023 edition (OR23), has 70 multiple-choice questions and a 110-minute limit. ACS also offers a brief version with 45 questions in 55 minutes. ACS publishes national norms instead of a pass mark, so ask your instructor how the score counts.
Preparing for the ACS Organic Chemistry Exam? Take a free readiness test and see which topics to study first. Or see the ACS Organic Chemistry Exam study guide.
Which ACS organic exam will your class use?
ACS lists several organic exams, and the length depends on the version your instructor chooses. The active exams in the ACS catalog look like this:
| Code | Version | Questions | Minutes |
|---|---|---|---|
| OR23 | 2023 full year (two forms) | 70 | 110 |
| OR20 | 2020 full year | 70 | 110 |
| OR18 | 2018 full year (two forms) | 70 | 110 |
| OR17 | 2017 full year (two forms) | 70 | 110 |
| OR16 | 2016 full year | 70 | 110 |
| OR21F | 2021 first term | 70 | 110 |
| OR17F | 2017 first term (two forms) | 70 | 110 |
| OR14F | 2014 first term | 70 | 110 |
| OR24B | 2024 brief (shortened) | 45 | 55 |
The catalog also lists two newer exams, a second-term exam (OR26S) and a first-term exam (OR27F), as in trial testing, with no question or time data yet. Ask your instructor for the code, because each code has its own norm sheet.
Two different paces
Do the division. The full-year exam gives you 110 minutes for 70 questions, about 94 seconds each. The brief exam gives 55 minutes for 45 questions, about 73 seconds each. A fixed time per question is only a rough guide, but the brief version leaves less room to get stuck on one problem.
What the brief version tells you about content
ACS says the brief exam covers the same content as the full-year exam with fewer items, for classes that do not have a two-hour block for the final. Its page lists the topics:
- Shape and stability, nomenclature and functional groups, isomers, acids and bases
- Nucleophilic substitution, elimination, addition reactions of alkenes and alkynes
- Reactions of alcohols and ethers, spectroscopy, radical reactions
- Conjugated systems and aromaticity, aromatic reactions
- Carbonyl chemistry, enols and enolates, multistep synthesis
That list is the closest thing to a syllabus on the page, and it shows no weight for any topic.
Norms, not a pass mark
ACS norm sheets show the percentile rank for each raw score, plus overall test statistics. OR23 has two sets: one for the standard count of correct answers and one for partial credit scoring. The standard OR23 sheet is built on the scores of 2,493 students from 45 institutions. A norm sheet tells you where a score sits among other students. It does not tell you what grade your course gives, and the pages we checked list no pass mark or cut score.
Instructors order the exams through ACS, and ACS asks them to send scores back so it can build norms. Students can buy official study materials and online practice exams from the ACS Exams Institute.
Frequently asked questions
How many questions are on the ACS Organic Chemistry exam?
The full-year exam, including OR23, has 70 questions. The brief version, OR24B, has 45. First-term exams such as OR21F have 70.
Is there a passing score on the ACS Organic Chemistry exam?
ACS publishes no passing score on the pages we checked. It publishes national norms, so ask your instructor how the result counts toward your grade.
How long is the ACS Organic Chemistry exam?
The full-year and first-term exams allow 110 minutes. The brief exam allows 55 minutes.
Does the brief exam cover less material?
ACS says it covers the same content as the full-year exam with fewer items.
Official sources
- ACS Exams Institute: exams catalog (questions and time limits)
- ACS Exams Institute: 2024 Organic Chemistry Exam, Brief (OR24B)
- ACS Exams Institute: 2023 Organic Chemistry Exam (OR23)
- ACS Exams Institute: national norms
- ACS Exams Institute: OR23 norm sheet (PDF)
- ACS Exams Institute: score reporting
Checked against the sources above on November 2, 2026. Exam bodies change fees and rules: confirm on the official page before you register.