ACS Practice Test

• Format confirmed for 2026: the full-year ACS General Chemistry exam (GC21) and the full-year Organic Chemistry exam (OR23) are each 70 multiple-choice items in 110 minutes. The newest full-year general chemistry edition is GC24 (2024, not yet normed), and a shortened 45-item, 55-minute Organic Chemistry Brief (OR24B) is also available. (source)
• New ACS exam editions released in 2025-2026: PC25 Preparatory Chemistry (50 items, 60 minutes), GC25F General Chemistry First Term (with partial-credit scoring), IA25 Instrumental Analysis, GB25D General-Organic-Biochemistry Condensed (60 items) and TP26 Toledo Placement (60 items in three 20-item parts). Exams in trial testing for 2025-26 include OR26S, BC26, GC27, GC27S, OR27F and DUCK27. (source) (source)
• Students cannot buy or self-register for an ACS exam: order forms are issued only to a chemistry department chair, and the 2026 price list (effective January 1 - December 31, 2026) charges the institution USD $2.50 per General Chemistry exam (25-95 copies) or $3.00 per Organic, Biochemistry or Physical Chemistry exam (10-20 copies). Any exam fee is paid by the department, not the student. (source) (source)
• Official study guides ("Preparing for Your ACS Examination" in General, Organic and Physical Chemistry, plus the new 164-page Biochemistry guide) cost USD $30.00 each at acsexamsinstitute.com. Online practice exams are $10 (50 items; analytical 30 items), tutorial exams with feedback are $15, and study-guide bundles are $34, $39 or $46. (source) (source) (source)
• Scoring is norm-referenced with right answers only and no penalty for guessing. On the GC21 composite norm (2,060 students, 17 institutions) the mean is 37.8 of 70, 50 correct is the 80th percentile and 60 correct is the 95th; on the OR23 norm (2,493 students, 45 institutions) the mean is 40.1 of 70, 50 correct is the 80th percentile and 60 is the 96th. (source) (source) (source)
• Norms newly published in 2026 include General Chemistry 2021, General Chemistry 2022 Second Term and Analytical Chemistry 2022; a norm-reduction tool now lets instructors recompute norms for 25 general and organic chemistry exams after removing items. (source) (source)
• Test-day rules: non-programmable calculators are allowed, no reference material is permitted, and all needed reference data (including the periodic table) is printed in the test booklet. ACS Exams no longer sells bubble sheets; a copyable answer sheet ships with every order and automated scoring is free, with score reports generated within 24 hours. (source) (source)
• Electronic delivery of ACS exams is still under development with the University of Massachusetts CESD (the OWL platform) and will require proctored computer labs; ACS exams remain paper-and-pencil administrations in 2026. (source)

Last verified: September 17, 2026 against the ACS Division of Chemical Education Examinations Institute (uwm.edu/acs-exams, acsexamsinstitute.com).